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1.
Data Brief ; 48: 109109, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37122929

ABSTRACT

The CAMCATT-AI4GEO extensive field experiment took place in Toulouse, a city in the southwest of France, from 14th to 25th June 2021 (with complementary measurements performed on the 6 September 2021). Its main objective was the acquisition of a new reference dataset on an urban site to support the development and validation of data products from the future thermal infrared (TIR) satellite missions such as TRISHNA (CNES/ISRO), LSTM (ESA) and SBG (NASA). With their high spatial (between 30-60m) and temporal (2-3 days) resolutions, the future TIR satellite data will allow a better investigation of the urban climate at the neighbourhood scale. However, in order to validate the future products of these missions such as LST, air temperature, comfort index and Urban Heat Island (UHI), there is a need to accurately characterise the organisation of the city in terms of 3D geometry, spectral optical properties and both land surface temperature and emissivity (LST and LSE) at several scales. In this context, the CAMCATT-AI4GEO field campaign provides a set of airborne VISNIR-SWIR (Visible Near InfraRed - ShortWave InfraRed) hyperspectral imagery, multispectral thermal infrared (TIR) imagery and 3D LiDAR acquisitions, together with a variety of ground data collected, for some of them, simultaneously to the flight. The ground dataset includes surface reflectance measured spectrally with ASD spectroradiometers and in six spectral bands spreading from shortwave to thermal infrared and for two viewing angles with a SOC410-DHR handheld reflectometer. It is completed with LST and LSE retrieved from thermal infrared radiance acquired in six spectral bands with CIMEL radiometers. It also includes meteorological data coming from four radio soundings (one of which was taken during the flight), data routinely collected at the Blagnac airport reference station as well as air temperature and humidity acquired using instrumented cars following two different itineraries. In addition, a link is provided to access the data routinely collected by the network of weather stations set up by Toulouse Metropole in the city and its surroundings. This data paper describes this new reference urban dataset which can be useful for many applications such as calibration/validation of at-surface radiance, LST and LSE data products as well as higher level products such as air temperature or comfort index. It also provides valuable opportunities for other applications in urban climate studies, such as supporting the validation of microclimate models.

2.
Toxicol In Vitro ; 42: 150-160, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28433809

ABSTRACT

Gold nanoparticles (AuNP) adsorb macromolecules to form a protein corona (PC) after systemic delivery, to which the kidney as the primary excretory organ is constantly exposed. The role of the PC on AuNP cell uptake and toxicity was investigated in vitro in human proximal tubule cells (HPTC) using 40 and 80nm branched polyethylenimine (BPEI), lipoic acid (LA) and polyethylene glycol (PEG) coated AuNP with or without (bare) PCs composed of human plasma (HP) or human serum albumin (HSA) for 0.25 to 24h. Time-dependent intracellular uptake, assessed by ICP-MS showed PC modulated cell uptake and cytotoxicity; with bare 40nm BPEI-AuNP showing the greatest responses. All AuNP showed minimal to no cytokine release. At the nontoxic dose, 40nm bare BPEI-AuNP significantly modified gene expression related to immunotoxicity, steatosis, and mitochondrial metabolism; while at the high dose, pathways of DNA damage and repair, apoptosis, fatty acid metabolism and heat shock response were modulated. HP corona BPEI-AuNP response was comparable to control. These studies clearly showed reduced uptake and cytotoxicity, as well as differentiated gene expression of AuNP with PCs, questioning the utility of in vitro studies using bare NP to assess in vivo effects. Significantly, only cationic bare BPEI-AuNP had HPTC uptake or cytotoxicity suggesting the relative safety of PEG and LA-AuNP as nanomedicine constructs.


Subject(s)
Gold , Kidney Tubules, Proximal/cytology , Metal Nanoparticles , Protein Corona/chemistry , Serum Albumin/chemistry , Cells, Cultured , Cytokines/metabolism , Gene Expression/drug effects , Gold/administration & dosage , Gold/chemistry , Gold/toxicity , Humans , Metal Nanoparticles/administration & dosage , Metal Nanoparticles/chemistry , Metal Nanoparticles/toxicity , Plasma/chemistry , Polyethylene Glycols/chemistry , Polyethyleneimine/chemistry , Thioctic Acid/chemistry
3.
J Appl Toxicol ; 36(2): 189-98, 2016 Feb.
Article in English | MEDLINE | ID: mdl-25976427

ABSTRACT

We developed an in vitro method to assess pet food ingredients safety. Canine bone marrow-derived mesenchymal stem cells (BMSC) were differentiated into enterocyte-like cells (ELC) to assess toxicity in cells representing similar patterns of exposure in vivo. The toxicological profile of clove leave oil, eugenol, guanosine monophosphate (GMP), GMP + inosine monophosphate, sorbose, ginger root extract, cinnamon bark oil, cinnamaldehyde, thyme oil, thymol and citric acid was assessed in BMSC and ELC. The LC50 for GMP + inosine monophosphate was 59.42 ± 0.90 and 56.7 ± 3.5 mg ml(-1) for BMSC and ELC; 56.84 ± 0.95 and 53.66 ± 1.36 mg ml(-1) for GMP; 0.02 ± 0.001 and 1.25 ± 0.47 mg ml(-1) for citric acid; 0.077 ± 0.002 and 0.037 ± 0.01 mg ml(-1) for cinnamaldehyde; 0.002 ± 0.0001 and 0.002 ± 0.0008 mg ml(-1) for thymol; 0.080 ± 0.003 and 0.059 ± 0.001 mg ml(-1) for thyme oil; 0.111 ± 0.002 and 0.054 ± 0.01 mg ml(-1) for cinnamon bark oil; 0.119 ± 0.0004 and 0.099 ± 0.011 mg ml(-1) for clove leave oil; 0.04 ± 0.001 and 0.028 ± 0.002 mg ml(-1) for eugenol; 2.80 ± 0.11 and 1.75 ± 0.51 mg ml(-1) for ginger root extract; > 200 and 116.78 ± 7.35 mg ml(-1) for sorbose. Lemon grass oil was evaluated at 0.003-0.9 in BMSC and .03-0.9 mg ml(-1) in ELC and its mechanistic effect was investigated. The gene toxicology studies showed regulation of 61% genes in CYP450 pathway, 37% in cholestasis and 33% in immunotoxicity pathways for BMSC. For ELC, 80% for heat shock response, 69% for beta-oxidation and 65% for mitochondrial energy metabolism. In conclusion, these studies provide a baseline against which differential toxicity of dietary feed ingredients can be assessed in vitro for direct effects on canine cells and demonstrate differential toxicity in differentiated cells that represent gastrointestinal epithelial cells.


Subject(s)
Animal Feed/toxicity , Bone Marrow/drug effects , Cytotoxins/toxicity , Enterocytes/drug effects , Mesenchymal Stem Cells/drug effects , Plant Oils/toxicity , Acrolein/analogs & derivatives , Acrolein/toxicity , Animals , Citric Acid/toxicity , Clove Oil/toxicity , Dogs , Eugenol/toxicity , Zingiber officinale/toxicity , Guanosine Monophosphate/toxicity , Inosine Monophosphate/toxicity , Oils, Volatile/toxicity , Pets , Plant Roots/toxicity , Sorbose/toxicity , Thymol/toxicity
4.
Toxicol In Vitro ; 29(2): 289-98, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25458622

ABSTRACT

In vitro models are useful tools to initially assess the toxicological safety hazards of food ingredients. Toxicities of cinnamaldehyde (CINA), cinnamon bark oil, lemongrass oil (LGO), thymol, thyme oil (TO), clove leaf oil, eugenol, ginger root extract (GRE), citric acid, guanosine monophosphate, inosine monophosphate and sorbose (SORB) were assessed in canine renal proximal tubule cells (CPTC) using viability assay and renal injury markers. At LC50, CINA was the most toxic (0.012mg/ml), while SORB the least toxic (>100mg/ml). Toxicities (LC50) of positive controls were as follows: 4-aminophenol (0.15mg/ml in CPTC and 0.083mg/ml in human PTC), neomycin (28.6mg/ml in CPTC and 27.1mg/ml in human PTC). XYL displayed lowest cytotoxic potency (LC50=82.7mg/ml in CPTC). In vivo renal injury markers in CPTC were not significantly different from controls. The LGO toxicity mechanism was analyzed using qPCR and electron microscopy. Out of 370 genes, 57 genes (15.4%) were significantly up (34, 9.1%) or down (23, 6.2%) regulated, with the most upregulated gene gsta3 (∼200-fold) and the most affected pathway being oxidative stress. LGO induced damage of mitochondria, phospholipid accumulation and lack of a brush border. Viability assays along with mechanistic studies in the CPTC model may serve as a valuable in vitro toxicity screening tool.


Subject(s)
Food Safety , Kidney Tubules, Proximal/cytology , Toxicity Tests/methods , Acrolein/analogs & derivatives , Acrolein/toxicity , Aminophenols/toxicity , Animals , Cell Survival/drug effects , Citric Acid/toxicity , Dogs , Eugenol/toxicity , Gene Expression Profiling , Zingiber officinale , Guanosine Monophosphate/toxicity , Humans , Inosine Monophosphate/toxicity , Oils, Volatile/toxicity , Plant Extracts/toxicity , Plant Oils/toxicity , Plant Roots , Sorbose/toxicity , Terpenes/toxicity , Thymol/toxicity , Thymus Plant , Xylitol/toxicity
5.
Water Sci Technol ; 66(6): 1325-32, 2012.
Article in English | MEDLINE | ID: mdl-22828313

ABSTRACT

Open-channel junctions are common occurrences in sewer networks and flow rate measurement often occurs near these singularities. Local flow structures are 3D, impact on the representativeness of the local flow measurements and thus lead to deviations in the flow rate estimation. The present study aims (i) to measure and simulate the flow pattern in a junction flow, (ii) to analyse the impact of the junction on the velocity distribution according to the distance from the junction and thus (iii) to evaluate the typical error derived from the computation of the flow rate close to the junction.


Subject(s)
Models, Theoretical , Sanitary Engineering/methods , Water Movements , Computer Simulation , Time Factors
6.
J Vet Pharmacol Ther ; 35 Suppl 1: 103-14, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22413798

ABSTRACT

Obtaining a biowaiver for topical drugs used in veterinary species faces many of the same challenges associated with human topicals. However, the skin of domestic animals varies anatomically and biochemically and experimental approaches to assess bioequivalence (BE) in veterinary species have challenges that are not often encountered with human skin. This is especially the situation with locally acting drugs. The focus of this paper is to address several of the challenges associated with (i) determining the BE of these locally acting drugs and (ii) critically examine the current technological advances that can act as a surrogate for clinical trials.


Subject(s)
Veterinary Drugs/pharmacokinetics , Administration, Topical , Animals , Dosage Forms , Drug Administration Routes , Legislation, Drug , Species Specificity , Therapeutic Equivalency , Veterinary Drugs/administration & dosage , Veterinary Drugs/chemistry
7.
AIP Adv ; 1(2): 22139, 2011 Jun.
Article in English | MEDLINE | ID: mdl-22125759

ABSTRACT

In this study, biodegradable acid anhydride copolymer microneedles containing quantum dots were fabricated by means of visible light dynamic mask micro-stereolithography-micromolding and inkjet printing. Nanoindentation was performed to obtain the hardness and the Young's modulus of the biodegradable acid anhydride copolymer. Imaging of quantum dots within porcine skin was accomplished by means of multiphoton microscopy. Our results suggest that the combination of visible light dynamic mask micro-stereolithography-micromolding and inkjet printing enables fabrication of solid biodegradable microneedles with a wide range of geometries as well as a wide range of pharmacologic agent compositions.

8.
Toxicol In Vitro ; 25(8): 2105-12, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21964474

ABSTRACT

Carbon fullerenes possess unique properties and their interactions with biomolecules have widespread applications. Functionalization of fullerenes with hydroxyl groups (fullerenols) can increase the solubility and potential for cellular interaction, but the health and safety effects of varying degrees of fullerene hydroxylation in biological systems is poorly understood. Existing reports regarding the toxicity and inflammatory potential of fullerenols give conflicting conclusions. To further elucidate the potential for toxicity of fullerenols, human epidermal keratinocytes (HEK) were exposed to fullerenols (low (C60(OH)20), medium (C60(OH)24), and high (C60(OH)32)) at concentrations ranging from 0.000544-42.5 µg/ml for 24 and 48 h. A statistically significant (p<0.05) decrease in viability with alamar Blue (aB) was noted only with C60(OH)32 at 42.5 µg/ml after 24 h. Nanoparticle (NP) controls showed minimal NP/assay interference of the three fullerenols with the aB viability assay. Normalized IL-8 concentration for C60(OH)20 was not significantly different from control, while C60(OH)24 and C60(OH)32 showed a significant decrease at 24 and 48 h. These results suggest that different hydroxylation of fullerenes caused no cytotoxicity or inflammation up to 8.55 µg/ml. These findings suggest that extrapolation across similar NP will be dependent upon surface chemistry and concentration which may affect the degree of agglomeration and thus biological effects.


Subject(s)
Fullerenes/toxicity , Keratinocytes/drug effects , Biological Transport , Cell Survival , Cells, Cultured , Fullerenes/chemistry , Fullerenes/metabolism , Humans , Hydroxylation , Interleukin-8/metabolism , Keratinocytes/metabolism , Keratinocytes/ultrastructure , Microscopy, Electron, Transmission , Photoelectron Spectroscopy , Spectrometry, Fluorescence
9.
Toxicol Sci ; 123(1): 264-80, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21642632

ABSTRACT

Sunscreens containing titanium dioxide (TiO(2)) and zinc oxide (ZnO) nanoparticles (NP) are effective barriers against ultraviolet B (UVB) damage to skin, although little is known about their disposition in UVB-damaged skin. Pigs were exposed to UVB that resulted in moderate sunburn. For in vitro studies, skin in flow-through diffusion cells were treated 24 h with four sunscreen formulations as follows: 10% coated TiO(2) in oil/water (o/w), 10% coated TiO(2) in water/oil (w/o), 5% coated ZnO in o/w, and 5% uncoated ZnO in o/w. TiO(2) (rutile, crystallite) primary particle size was 10 × 50 nm with mean agglomerates of 200 nm (range ca. 90 nm--460 nm); mean for ZnO was 140 nm (range ca. 60--200 nm). Skin was processed for light microscopy, scanning (SEM) and transmission electron microscopy (TEM), and time-of-flight secondary ion mass spectrometry (TOF-SIMS). UVB-exposed skin had typical sunburn histology. TEM showed TiO(2) NP 17 layers into stratum corneum (SC), whereas ZnO remained on the surface. TOF-SIMS showed TiO(2) and ZnO epidermal penetration in both treatments. Perfusate analyzed by TEM/energy dispersive x-ray spectroscopy or inductively coupled plasma mass spectrometry detected no Ti or Zn, indicating minimal transdermal absorption. In vivo, skin was dosed at 24 h occluded with formulations and at 48 h. TiO(2) NP in o/w formulation penetrated 13 layers into UVB-damaged SC, whereas only 7 layers in normal skin; TiO(2) in w/o penetrated deeper in UVB-damaged SC. Coated and uncoated Zn NP in o/w were localized to the upper one to two SC layers in all skin. By SEM, NP were localized as agglomerates in formulation on the skin surface and base of hair. TOF-SIMS showed Ti within epidermis and superficial dermis, whereas Zn was limited to SC and upper epidermis in both treatments. In summary, UVB-damaged skin slightly enhanced TiO(2) NP or ZnO NP penetration in sunscreen formulations but no transdermal absorption was detected.


Subject(s)
Metal Nanoparticles/toxicity , Skin/drug effects , Sunburn/drug therapy , Sunscreening Agents/toxicity , Titanium/toxicity , Zinc Oxide/toxicity , Animals , Erythema/etiology , Erythema/pathology , Erythema/prevention & control , In Vitro Techniques , Metal Nanoparticles/radiation effects , Metal Nanoparticles/ultrastructure , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Particle Size , Skin/pathology , Skin/radiation effects , Skin/ultrastructure , Sunburn/etiology , Sunburn/pathology , Sunscreening Agents/pharmacokinetics , Swine/physiology , Titanium/pharmacokinetics , Titanium/radiation effects , Ultraviolet Rays/adverse effects , Zinc Oxide/pharmacokinetics , Zinc Oxide/radiation effects
10.
Water Sci Technol ; 61(8): 2021-6, 2010.
Article in English | MEDLINE | ID: mdl-20388999

ABSTRACT

Many investigations have been carried out in order to develop models which allow the understanding of complex physical processes involved in urban flooding. The modelling of the interactions between overland flows on streets and flooding flows from rivers and sewer networks is one of the main objectives of recent and current research programs in hydraulics and urban hydrology. However, the modelling of the discharge distribution in the street network with crossroad needs further research due to the complexity of the flow through junctions. This paper outlines the ability of the improved one-dimensional CANOE software to simulate the street flows through the virtual network (developed under the Hy(2)Ville French National project framework) with several cross-roads. The improvements are done by adding in CANOE the energy losses coefficients deriving from the calibration phase based on the experimental study of the flow through small scale physical model of cross-road channels. Comparisons between 1D and 2D simulated distribution of discharges through the virtual network show a good agreement for the global distribution. However, large differences are observed focusing on the individual cross-road intersections in the virtual network.


Subject(s)
Cities , Floods , Models, Theoretical , Software , Calibration
11.
Water Sci Technol ; 60(4): 927-34, 2009.
Article in English | MEDLINE | ID: mdl-19700831

ABSTRACT

Many investigations have been carried out in order to develop models which allow the linking of complex physical processes involved in urban flooding. The modelling of the interactions between overland flows on streets and flooding flows from rivers and sewer networks is one of the main objectives of recent and current research programs in hydraulics and urban hydrology. This paper outlines the original one-dimensional linking of heavy rainfall-runoff in urban areas and flooding flows from rivers and sewer networks under the RIVES project framework (Estimation of Scenario and Risks of Urban Floods). The first part of the paper highlights the capacity of Canoe software to simulate the street flows. In the second part, we show the original method of connection which enables the modelling of interactions between processes in urban flooding. Comparisons between simulated results and the results of Despotovic et al. or Gomez & Mur show a good agreement for the calibrated one-dimensional connection model. The connection operates likes a manhole with the orifice/weir coefficients used as calibration parameters. The influence of flooding flows from river was taken into account as a variable water depth boundary condition.


Subject(s)
Cities , Drainage, Sanitary , Floods , Models, Theoretical , Rain , Rivers , Water Movements , Computer Simulation , Software
12.
Toxicol Appl Pharmacol ; 234(2): 222-35, 2009 Jan 15.
Article in English | MEDLINE | ID: mdl-18983864

ABSTRACT

Single-walled carbon nanotubes (SWCNT), fullerenes (C(60)), carbon black (CB), nC(60), and quantum dots (QD) have been studied in vitro to determine their toxicity in a number of cell types. Here, we report that classical dye-based assays such as MTT and neutral red (NR) that determine cell viability produce invalid results with some NM (nanomaterials) due to NM/dye interactions and/or NM adsorption of the dye/dye products. In this study, human epidermal keratinocytes (HEK) were exposed in vitro to CB, SWCNT, C(60), nC(60), and QD to assess viability with calcein AM (CAM), Live/Dead (LD), NR, MTT, Celltiter 96 AQueous One (96 AQ), alamar Blue (aB), Celltiter-Blue (CTB), CytoTox Onetrade mark (CTO), and flow cytometry. In addition, trypan blue (TB) was quantitated by light microscopy. Assay linearity (R(2) value) was determined with HEK plated at concentrations from 0 to 25,000 cells per well in 96-well plates. HEK were treated with serial dilutions of each NM for 24 h and assessed with each of the viability assays. TB, CAM and LD assays, which depend on direct staining of living and/or dead cells, were difficult to interpret due to physical interference of the NM with cells. Results of the dye-based assays varied a great deal, depending on the interactions of the dye/dye product with the carbon nanomaterials (CNM). Results show the optimal high throughput assay for use with carbon and noncarbon NM was 96 AQ. This study shows that, unlike small molecules, CNM interact with assay markers to cause variable results with classical toxicology assays and may not be suitable for assessing nanoparticle cytotoxicity. Therefore, more than one assay may be required when determining nanoparticle toxicity for risk assessment.


Subject(s)
Nanoparticles/toxicity , Cell Line , Cell Survival/drug effects , Drug Evaluation, Preclinical , Flow Cytometry , Fluoresceins , Fluorescent Dyes , Humans , Keratinocytes/drug effects , Light , Microscopy, Electron, Transmission , Oxazines , Quantum Dots , Scattering, Radiation , Spectrophotometry, Ultraviolet , Tetrazolium Salts , Thiazoles , Trypan Blue , Xanthenes
13.
Biofabrication ; 1(4): 041001, 2009 Dec.
Article in English | MEDLINE | ID: mdl-20661316

ABSTRACT

One promising option for transdermal delivery of protein- and nucleic acid-based pharmacologic agents involves the use of microneedles. However, microneedle-generated pores may allow microorganisms to penetrate the stratum corneum layer of the epidermis and cause local or systemic infection. In this study, microneedles with antimicrobial functionality were fabricated using two-photon polymerization-micromolding and pulsed laser deposition.The antibacterial activity of the silver-coated organically modified ceramic (Ormocer)microneedles was demonstrated using an agar diffusion assay. Human epidermal keratinocyte viability on the Ormocer surfaces coated with silver was similar to that on uncoated Ormocer surfaces. This study indicates that coating microneedles with silver thin films using pulsed laser deposition is a useful and novel approach for creating microneedles with antimicrobial functionality.


Subject(s)
Ceramics/chemistry , Drug Delivery Systems/instrumentation , Microtechnology/methods , Needles , Silanes/chemistry , Silver/chemistry , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/chemistry , Biotechnology , Cell Survival/drug effects , Diffusion , Humans , Keratinocytes , Microbial Sensitivity Tests , Microscopy, Electron, Scanning , Organically Modified Ceramics , Silanes/administration & dosage , Silver/administration & dosage , Staphylococcus aureus/drug effects
14.
Skin Pharmacol Physiol ; 21(3): 166-80, 2008.
Article in English | MEDLINE | ID: mdl-18523414

ABSTRACT

Quantum dot (QD) nanoparticles have received attention due to their fluorescent characteristics and potential use in medical applications. Skin penetration is one of the major routes of exposure for nanoparticles to gain access to a biological system. QD655 and QD565 coated with carboxylic acid were studied for 8 and 24 h in flow-through diffusion cells with flexed, tape-stripped and abraded rat skin to determine if these mechanical actions could perturb the barrier and affect penetration. Nonflexed skin did not show QD penetration at 8 or 24 h. Flexed skin showed an increase in QD on the surface of skin but no penetration at 8 and 24 h. Tape-stripped skin depicted QD only on the surface of the viable epidermis. QD655 penetrated into the viable dermal layers of abraded skin at both 8 and 24 h, while QD565 was present only at 24 h. QD were not detected in the perfusate by fluorescence and inductively coupled plasma-optical emission spectroscopy analysis for cadmium at any time point. These results indicate that the rat skin penetration of QD655 and QD565 is primarily limited to the uppermost stratum corneum layers of intact skin. Barrier perturbation by tape stripping did not cause penetration, but abrasion allowed QD to penetrate deeper into the dermal layers.


Subject(s)
Quantum Dots , Skin Absorption , Skin/metabolism , Adhesives , Administration, Cutaneous , Animals , Dermabrasion , Microscopy, Confocal , Permeability , Rats , Rats, Wistar , Spectrometry, Fluorescence
15.
JOM (1989) ; 60(3): 33-37, 2008 Mar 01.
Article in English | MEDLINE | ID: mdl-20617106

ABSTRACT

The therapeutic application of nanomaterials has been a focus of numerous studies in the past decade. Due to its unique redox properties, cerium oxide (ceria) is finding widespread use in the treatment of medical disorders caused by the reactive oxygen intermediates (ROI). The radical-scavenging role of ceria nanoparticles (nanoceria) have been established, as well as the autocatalytic ability of nanoceria to regenerate under various environmental conditions. The synthesis of nanoceria in biocompatible media has also been reported along with cell viability in order to determine the potential use of nanoceria in biomedical applications.

16.
J Appl Toxicol ; 28(4): 543-53, 2008 May.
Article in English | MEDLINE | ID: mdl-17966119

ABSTRACT

Jet propellant (JP)-8, the primary jet fuel used by the U.S. military, consists of hydrocarbon-rich kerosene base commercial jet fuel (Jet-A) plus additives DC1-4A, Stadis 450 and diethylene glycol monomethyl ether. Human epidermal keratinocytes (HEK) were exposed to JP-8, aliphatic hydrocarbon (HC) fuel S-8 and aliphatic HC pentadecane (penta), tetradecane (tetra), tridecane (tri) and undecane (un) for 5 min. Additional studies were conducted with signal transduction pathway blockers parthenolide (P; 3.0 microm), isohelenin (I; 3.0 microm), SB 203580 (SB; 13.3 microm), substance P (SP; 3.0 microm) and recombinant human IL-10 (rHIL-10; 10 ng ml(-1)). In the absence of inhibitors, JP-8 and to a lesser extent un and S-8, had the greatest toxic effect on cell viability and inflammation suggesting, as least in vitro, that synthetic S-8 fuel is less irritating than the currently used JP-8. Each inhibitor significantly (P < 0.05) decreased HEK viability. DMSO, the vehicle for P, I and SB, had a minimal effect on viability. Overall, IL-8 production was suppressed at least 30% after treatment with each inhibitor. Normalizing data relative to control indicate which inhibitors suppress HC-mediated IL-8 to control levels. P was the most effective inhibitor of IL-8 release; IL-8 was significantly decreased after exposure to un, tri, tetra and penta but significantly increased after JP-8 exposure compared with controls. Inhibitors were not effective in suppressing IL-8 release in JP-8 exposures to control levels. This study shows that inhibiting NF-kappa B, which appears to play a role in cytokine production in HC-exposed HEK in vitro, may reduce the inflammatory effect of HC in vivo.


Subject(s)
Alkanes/toxicity , Anti-Inflammatory Agents/pharmacology , Hydrocarbons/toxicity , Irritants/toxicity , Keratinocytes/drug effects , Anti-Inflammatory Agents/metabolism , Cell Survival/drug effects , Cells, Cultured , Cytokines/metabolism , Humans , Imidazoles/pharmacology , Interleukin-10/metabolism , Keratinocytes/metabolism , Keratinocytes/pathology , NF-kappa B/antagonists & inhibitors , NF-kappa B/metabolism , Protein Kinase Inhibitors/pharmacology , Pyridines/pharmacology , Recombinant Proteins/metabolism , Sesquiterpenes/pharmacology , Substance P/metabolism , Time Factors
17.
SAR QSAR Environ Res ; 18(5-6): 579-93, 2007.
Article in English | MEDLINE | ID: mdl-17654338

ABSTRACT

A system coefficient approach is proposed for quantitative assessment of the solvent effects on membrane absorption from chemical mixtures. The complicated molecular interactions are dissected into basic molecular interaction forces via Abraham's linear solvation energy relationship (LSER). The molecular interaction strengths of a chemical are represented by a set of solute descriptors, while those of a membrane/chemical mixture system are represented by a set of system coefficients. The system coefficients can be determined by using a set of probe compounds with known solute descriptors. Polydimethylsiloxane (PDMS) membrane-coated fibres and 32 probe compounds were used to demonstrate the proposed approach. When a solvent was added into the chemical mixture, the system coefficients were altered and detected by the system coefficient approach. The system coefficients of the PDMS/water system were (0.09, 0.49, -1.11, -2.36, -3.78, 3.50). When 25% ethanol was added into the PDMS/water system, the system coefficients were altered significantly (0.38, 0.41, -1.18, -2.07, -3.40, 2.81); and the solvent effect was quantitatively described by the changes in the system coefficients (0.29, -0.08, -0.07, 0.29, 0.38, -0.69). The LSER model adequately described the experimental data with a correlation coefficient (r(2)) of 0.995 and F-value of 1056 with p-value less than 0.0001.


Subject(s)
Dimethylpolysiloxanes/chemistry , Membranes, Artificial , Models, Biological , Models, Chemical , Silicones/chemistry , Absorption , Dimethylpolysiloxanes/metabolism , Kinetics , Quantitative Structure-Activity Relationship , Regression Analysis , Silicones/metabolism , Solvents/chemistry
18.
J Nanosci Nanotechnol ; 7(4-5): 1284-97, 2007.
Article in English | MEDLINE | ID: mdl-17450891

ABSTRACT

Carbon nanotubes are novel materials with unique physical and chemical properties, and have been considered for use in numerous technological applications. More recently, attention has turned to the unique biological and medical properties of these materials. In this review, the processing, chemical properties, physical properties, nucleic acid interaction, cell interaction, and toxicologic properties of nanotubes are described. Finally, future directions in this area are discussed.


Subject(s)
Biocompatible Materials/chemistry , Biophysics/methods , Carbon/chemistry , DNA/chemistry , Nanotechnology/methods , Nanotubes, Carbon/chemistry , Tissue Engineering/methods , Animals , Cell Line , Humans , Microscopy , Microscopy, Electron, Transmission , Neurons/metabolism , Nucleic Acids/chemistry , Time Factors
19.
Water Sci Technol ; 54(6-7): 75-82, 2006.
Article in English | MEDLINE | ID: mdl-17120636

ABSTRACT

This study focuses on the discharge distribution in an intersection of four channels, similar to a city crossroad. The channels and the intersection are all horizontal. Flow enters through two of the channels, and leaves through the other two. The flow is subcritical everywhere, and flow depths are controlled by vertical weirs at the exits of the outlet channels. The main variables that are measured are the flow rates in the four channels. When the weir heights in the outlet channels are the same, the ratio of flow rates in the outlet channels depends only on the ratio of flow rates in the inlet channels; if the outlet conditions are different, other parameters, such as the total flow rate also become important. The flow has also been simulated numerically using a solution of the 1-D Saint Venant equations, with a simple model to predict flow distribution in the intersection. A comparison with the experimental data shows that this model works well for the limited range of experimental conditions studied here. However, further work is needed on a wider range of conditions, closer to real conditions, before the model can be considered valid for practical applications.


Subject(s)
Cities , Disasters , Models, Theoretical , Rain , Water Movements , Computer Simulation , Research Design
20.
Toxicol Sci ; 89(1): 188-204, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16221965

ABSTRACT

The rate and extent of dermal absorption are important in the analysis of risk from dermal exposure to toxic chemicals and for the development of topically applied drugs, barriers, insect repellents, and cosmetics. In vitro flow-through cells offer a convenient method for the study of dermal absorption that is relevant to the initial processes of dermal absorption. This study describes a physiologically based pharmacokinetic (PBPK) model developed to simulate the absorption of organophosphate pesticides, such as parathion, fenthion, and methyl parathion through porcine skin with flow-through cells. Parameters related to the structure of the stratum corneum and solvent evaporation rates were independently estimated. Three parameters were optimized based on experimental dermal absorption data, including solvent evaporation rate, diffusivity, and a mass transfer factor. Diffusion cell studies were conducted to validate the model under a variety of conditions, including different dose ranges (6.3-106.9 microg/cm2 for parathion; 0.8-23.6 microg/cm2 for fenthion; 1.6-39.3 microg/cm2 for methyl parathion), different solvents (ethanol, 2-propanol and acetone), different solvent volumes (5-120 microl for ethanol; 20-80 microl for 2-propanol and acetone), occlusion versus open to atmosphere dosing, and corneocyte removal by tape-stripping. The study demonstrated the utility of PBPK models for studying dermal absorption, which can be useful as explanatory and predictive tools that may be used for in silico hypotheses generation and limited hypotheses testing. The similarity between the overall shapes of the experimental and model-predicted flux/time curves and the successful simulation of altered system conditions for this series of small, lipophilic compounds indicated that the absorption processes that were described in the model successfully simulated important aspects of dermal absorption in flow-through cells. These data have direct relevance to topical organophosphate pesticide risk assessments.


Subject(s)
Models, Biological , Organothiophosphorus Compounds/pharmacokinetics , Skin Absorption/physiology , Skin/metabolism , Administration, Cutaneous , Animals , Dose-Response Relationship, Drug , Fenthion/pharmacokinetics , In Vitro Techniques , Insecticides/pharmacokinetics , Methyl Parathion/pharmacokinetics , Parathion/pharmacokinetics , Risk Assessment , Skin Physiological Phenomena , Solubility , Swine
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