Search results for "Phthalate"
showing 10 items of 104 documents
Risk assessment of exposure to phthalates in breastfeeding women using human biomonitoring
2020
In this study, we assessed the presence of 14 phthalate metabolites in the urine of 104 lactating mothers from Valencia (Spain) who took part in the human biomonitoring project BETTERMILK. Nine of the metabolites studied showed detection frequencies >80%, whereas the rest of the metabolites presented low detection frequencies (<5%). The concentrations ranged from <LoQ to 1291 ng/mL with monoethyl phthalate showing the highest concentration, with a geometric mean of 34.90 ng/mL. In general, the phthalate metabolite levels quantified in the present study were lower than the urinary levels found in previous studies that involved lactating mothers. The consumption of packaged juices and the fre…
Internal exposure of the general population to DEHP and other phthalates--determination of secondary and primary phthalate monoester metabolites in u…
2003
A number of phthalates and their metabolites are suspected of having teratogenic and endocrine disrupting effects. Especially the developmental and reproductive effects of di(2-ethylhexyl)phthalate (DEHP) are under scrutiny. In this study we determined the concentrations of the secondary, chain oxidized monoester metabolites of DEHP, mono(2-ethyl-5-hydroxyhexyl)phthalate (5OH-MEHP) and mono(2-ethyl-5-oxo-hexyl)phthalate (5oxo-MEHP) in urine samples from the general population. The utilization of the secondary metabolites minimized any risk of contamination by the ubiquitously present phthalate parent compounds. Included in the method were also the simple monoester metabolites of DEHP, dioct…
Long-term results of the use of silicone sheets after diskectomy in the temporomandibular joint: clinical, radiographic and histopathologic findings
1999
The aim of the present study was to evaluate the long-term results of a group of patients who had the disk of the temporomandibular joint (TMJ) removed and permanently replaced by a silicone sheet. The study group comprised 48 patients, treated in the period from 1983 to 1993. In eight patients, the implants had to be removed after an average interval of 5.6 years and they were submitted for histopathological examination. Twenty-five of the 40 patients with silastic implants in place, and five of the 8 patients who had their implants removed, were available for long-term follow-up (mean interval of 7.0 years, SD 2.8 years). Clinical function was rated according to the Helkimo Dysfunction In…
A miniaturized method for estimating di(2-ethylhexyl) phthalate in bivalves as bioindicators.
2012
This work has developed a miniaturized method based on matrix solid phase dispersion (MSPD), using C18 as dispersant and acetonitrile-water as eluting solvent, for the analysis of di(2-ethylhexyl) phthalate (DEHP) in biota samples by capillary liquid chromatography coupled to in-tube solid phase microextraction and diode array detection. Recovery studies showed that the combination of C18-Florisil® was optimal using low amount of samples (0.1 g) and with low volumes of acetonitrile-water (2.6 mL 1:3.25, v/v). The sample is processed in less than 30 min, no evaporation step is required. The proposed method was applied to the analysis of DEHP in mussels and of the coastal waters in which they…
Biomonitoring of Phthalates, Bisphenols and Parabens in Children: Exposure, Predictors and Risk Assessment
2021
Exposure to emerging contaminants, such as phthalates, bisphenols and parabens in children has been associated with possible neurodevelopment and endocrine alterations. In the present study, the biomonitoring of biomarkers in children (5–12 years old) from the Valencia Region (Spain) have been implemented using urines from the BIOVAL program. More than 75% of the children studied (n = 562) were internally exposed (>
Polydimethylsiloxane (silicone rubber) brooch as a personal passive air sampler for semi-volatile organic compounds
2018
Exposure assessments conducted using a personal sampler include the contribution of human activities to exposure that is neglected when using a stationary air sampler. This study evaluated the uptake characteristics and application of the polydimethylsiloxane (PDMS or silicone rubber) brooch as a personal passive air sampler (PPAS) for measuring concentrations of two groups of semi-volatile organic compounds (SVOCs), namely phthalates and organophosphate esters (OPEs), indoors in proximity to the breathing zone. Uptake rates of the PDMS brooch were calibrated against a personal low volume active air sampler (PLV-AAS) co-deployed on each of five study participants working in offices for 8 hs…
Expression of Putative Fatty Acid Transporter Genes Are Regulated by Peroxisome Proliferator-activated Receptor α and γ Activators in a Tissue- and I…
1998
Regulation of gene expression of three putative long-chain fatty acid transport proteins, fatty acid translocase (FAT), mitochondrial aspartate aminotransferase (mAspAT), and fatty acid transport protein (FATP), by drugs that activate peroxisome proliferator-activated receptor (PPAR) alpha and gamma were studied using normal and obese mice and rat hepatoma cells. FAT mRNA was induced in liver and intestine of normal mice and in hepatoma cells to various extents only by PPARalpha-activating drugs. FATP mRNA was similarly induced in liver, but to a lesser extent in intestine. The induction time course in the liver was slower for FAT and FATP mRNA than that of an mRNA encoding a peroxisomal en…
Multicomponent solid dispersion as a formulation strategy to improve drug permeation: A case study on the anti-colorectal cancer irinotecan
2019
Abstract Multicomponent solid dispersions (MSD)s are frequently proposed as efficient drug delivery systems to improve drug solubility and bioavailability. In this study, the effects of specific excipients, such as mannitol, inulin, poly(methyl methacrylate-co-methacrylic)acid (PMMA) and cellulose acetate phthalate (CAP) have been tested to potentially improve irinotecan (IRN) permeation in the intestinal tract with the intention to protect the drug from the gastric environment. MSDs were formulated as microparticles by Spray-Drying technique. Raw materials and microparticles have been characterized by FTIR analysis to determine hydrogen bonding. SEM images were recorded to investigate morp…
Chromogenic Detection of Nerve Agent Mimics by Mass Transport Control at the Surface of Bifunctionalized Silica Nanoparticles
2010
Chemical warfare (CW) agents are toxic chemicals that have been used in several terrorist attacks in recent years. Among CW species, nerve agents are probably the most dangerous; their high toxicity and facile synthesis underscores the need to detect these lethal compounds with quick, reliable procedures. Analytical methods based on enzymatic assays and physical measurements have generally been used to detect these hazards. However, these protocols usually have limitations such as low selectivity, poor portability, and a certain level of complexity. In recent years, several chromogenic and fluorogenic sensors, and reagents for the detection of nerve agents have been described. For instance,…
On the use of PET-LCP copolymers as compatibilizers for PET/LCP blends
1996
Copolyesters of poly[ethylene terephthalate) (PET) with a liquid crystalline polymer (LCP), SBH 1:1:2, have been synthesized by the polycondensation, carried out in the melt at temperatures up to 300 degrees C of sebacic acid (S), 4,4'-dihydroxybiphenyl (B), and 4-hydroxybenzoic acid (H) in the presence of PET. The PET-SBH copolyesters have been characterized by differential scanning calorimetry, scanning electron microscopy, X-ray diffraction, etc., and the relationships between properties and preparation conditions are discussed. The copolyesters show a biphasic nature, which is more evident for the products synthesized with a thermal profile comprising relatively lower temperatures (220-…