Biomedical subjects

N Olea

Publications and source records attributed to N Olea.

At least 19 recordsLinked to original sources

PubMed2007

Oestrogenicity of paper and cardboard extracts used as food containers.

Bisphenol-A (BPA), dibutyl phthalate (DBP), and di-2-ethylhexyl phthalate (DEHP), which are common chemical residues in food-packaging materials, were investigated in paper and cardboard containers used for take-away food. The oestrogenicity of aqueous extracts was tested in E-Screen bioassay and analysis carried out by high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC/MS). Oestrogenicity was demonstrated in 90% of extracts (geometric mean [GM] = 11.97 pM oestradiol equivalents g(-1)). DEHP, DBP, and BPA (GM = 341.74, 37.59, and 2.38 ng g(-1) of material) were present in 77.50, 67.50, and 47.50% of samples, respectively. In bivariate analyses, no significant association was found between the levels of these chemicals and oestrogenicity in cardboard/paper extracts. A close-to-significant association was found between oestrogenicity and DBP (beta = 1.25; p = 0.06) in paper extracts, which reached statistical significance in multivariate analysis (beta = 1.61; p = 0.03). Paper and cardboard used in food packaging may contribute to the inadvertent exposure of consumers to endocrine-disrupting chemicals.

Benzhydryl Compounds↗

PubMed2006

Organochlorine pesticides in placentas from Southern Spain and some related factors.

During pregnancy, lipophilic xenobiotics stored in maternal adipose tissue can be mobilized and enter her blood circulation and reach the placenta. This study measured residues of oestrogen-mimicking organochlorine pesticides (OCs) in 150 placenta samples from women in Southern Spain. OCs were extracted from placenta by solid-liquid technique and purified by preparative liquid chromatography. Gas chromatography/electron-capture detection and mass spectrometry were used to identify and quantify p,p'-DDT and congeners/metabolites, endosulphan and congeners/metabolites, lindane, aldrin/dieldrin/endrin, hexachlorobenzene, methoxychlor and mirex. A mean of eight pesticides per placenta were detected (range, 3-15 pesticides). Endosulphan-ether, endosulphan-diol, endosulphan-I, p,p'-DDE, o,p'-DDD, p,p'-DDT, o,p'-DDT and lindane were detected in >or=50% of samples; p,p'-DDE was the most frequent (96.03%), followed by endosulphan-diol (76.86%) and lindane (74.17%). Presence of more pesticides was significantly associated with lower birth weight. Mean concentration of p,p'-DDE was 2.37+/-2.80 ng/g of placenta or 76.62+/-104.85 ng/g of lipid. Higher maternal body mass index was significantly associated with higher endosulphan concentrations in placenta, and greater maternal weight gain was significantly associated with higher p,p'-DDE concentrations. Prenatal exposure to OC xenoestrogens may be a causative factor in adverse reproductive health trends, and further studies are required to identify and describe pathways of this exposure to enhance preventive measures.

Adult↗

PubMed2006

Post-testicular changes in the density and distribution of intramembrane particles of stallion sperm surface domains.

Freeze-fracture replicas of stallion spermatozoa, collected from the proximal caput, corpus and cauda epididymides regions, were analyzed by electron microscopy to explore the distribution and density of intramembrane particles (IMP). Conspicuous differences in density and arrangement of the IMP were observed in the different topographical domains of mature and immature spermatozoa. A reduction of IMP, especially remarkable in the post-acrosomal domain, was observed in mature epididymal spermatozoa when compared with samples collected from ductuli efferentes. Some structural species-specific differences were also observed. The significance of these changes has not been determined, but remodeling of membrane components during developmental processes constitutes a fine control mechanism to ensure that key molecules are in the correct membrane position and during an appropriate timeframe to mediate fertilization.

Animals↗

PubMed2006

PBDEs and PBBs in the adipose tissue of women from Spain.

Polybromodiphenyl ethers (PBDEs) and polybromobiphenyls (PBBs) were investigated in adipose tissue of women living in Southeastern Spain. Mean Sigma PBDE (BDE 28, 75, 71, 47, 66, 77, 100, 119, 99, 85, 154, 153, 138, and 183) and Sigma PBB (PBB 18, 29, 31, 22, 38, 37, 53, 52, 49, 75, 80, 56, 77, 103, 101, 155, 154, 153, and 169) levels were 3.85 and 0.36 ng/g of lipid, respectively. Among PBDEs, congeners 153, 47, 183, 99, and 100 were the most frequent and abundant and together constituted 96% of the total amount of PBDEs in adipose tissue. Concentrations of PBDEs in this population were similar to those reported in other parts of Spain and in Swedish and Belgium populations but lower than those found in other Western countries. Among PBB congeners studied, PBB 153 presented the highest concentrations and contributed 79% of all PBBs. There are no published data on PBB congeners in adipose tissues of the Spanish population for comparison, but the levels found were similar to those described in other European countries. Further research is needed to determine trends in human exposure to PBDEs and PBBs and to explore putative effects on human health.

Adipose Tissue↗

PubMed2006

Induction of apoptosis in prostate tumor PC-3 cells and inhibition of xenograft prostate tumor growth by the vanilloid capsaicin.

Capsaicin, the pungent ingredient of hot chilli pepper, has been recently shown to induce apoptosis in several cell lines through a not well known mechanism. Here, we investigated the role of the vanilloid capsaicin in the death regulation of the human cancer androgen-resistant cell line PC-3. Capsaicin inhibited the growth of PC-3 with an IC(50) of 20 microM cells and induced cell apoptosis, as assessed by flow cytometry and nuclei staining with DAPI. Capsaicin induced apoptosis in prostate cells by a mechanism involving reactive oxygen species generation, dissipation of the mitochondrial inner transmembrane potential (DeltaPsi(m)) and activation of caspase 3. Capsaicin-induced apoptosis was not reduced by the antagonist capsazepine in a dose range from 0.1 microM to 20 microM, suggesting a receptor-independent mechanism. To study the in vivo effects of capsaicinoids, PC-3 cells were grown as xenografts in nude mice. Subcutaneous injection of either capsaicin or capsazepine (5 mg/kg body weight) in nude mice suppressed PC-3 tumor growth in all tumors investigated and induced apoptosis of tumor cells. Our data show a role for capsaicin against androgen-independent prostate cancer cells in vitro and in vivo and suggest that capsaicin is a promising anti-tumor agent in hormone-refractory prostate cancer, which shows resistance to many chemotherapeutic agents.

Androgens↗

PubMed2005

Environmental and lifestyle factors for organochlorine exposure among women living in Southern Spain.

Southern Spain has the largest area of intensive greenhouse agriculture in Europe, and may constitute a special case of occupational and female exposure, because this type of farming requires considerable pesticide use and employs many women. We measured adipose tissue levels of 14 organochlorine pesticides in 458 women living in this area and analyzed the relationship between pesticide level/presence and sociodemographic characteristics, reproductive history or life-style factors that may influence this exposure. Pesticide presence was determined by gas chromatography with electron-capture detector. All fat samples were positive for 1 residue. DDT or metabolites were found in 98.25%, with mean value of 660 ngg(-1) of lipid. p,p'-DDE level was higher in women who were older, with lower educational level or obese. Almost 70% had measurable levels of endosulfan and/or metabolites, with a mean total value of 38.8 ngg(-1) of lipid. Endosulfan-I exposure was higher in women with shorter residence in rural settings and more frequent in women with 3 children. 52.62% were exposed to 1 of aldrin-dieldrin-endrin group. Endrin was more frequent in women who were younger, with higher educational level or no agricultural working experience; dieldrin was more frequent in women who were older, with lower educational level or more children. Finally, lindane residues were found in 39.30%. Lindane levels were higher in women who breastfed longer or had more children. Research is required on women occupationally exposed to a selected group of organochlorine pesticides, especially those of reproductive age, as a basis for preventive action.

Adipose Tissue↗

PubMed2002

Determination of endocrine-disrupting pesticides and polychlorinated biphenyls in human serum by GC-ECD and GC-MS-MS and evaluation of contributions to the uncertainty of the results.

The chemicals endosulfan-alpha, endosulfan-beta, endosulfan sulfate, endosulfan ether, endosulfan lactone, PCB-21, PCB-48, PCB-61, and PCB-136 have been determined in 100 serum samples from women living in agricultural areas of Almería (Spain). The study includes a surgically treated breast cancer patient and a matching group of women with no sign of estrogenic-dependent disease. The determination was performed by gas chromatography with electron capture detection (GC-ECD) and tandem mass spectrometry (GC-MS-MS). Recovery, precision, linear range, detection limit (LOD), and quantification limit (LOQ) were calculated for each pesticide as was the expanded uncertainty (U). The method was evaluated for our laboratory and could be applied to subsequent results with relevant quality-control data. Comparison of the results was performed. The advantage of MS-MS over ECD for determination of endocrine-disrupting compounds in complex matrices is presented. The most commonly encountered pesticide was endosulfan-alpha. Endosulfan-beta and the PCB-48 congener were detected at concentrations lower than their LOQ. Endosulfan sulfate, endosulfan ether, endosulfan lactone, PCB-21, PCB-61 and PCB-136 were not found in any of the serum samples analysed.

Breast Neoplasms↗

PubMed2002

The effect of AH 26 and AH Plus on MCF-7 breast cancer cell proliferation in vitro.

AIM: The purpose of this study was to determine whether AH 26 and AH Plus have in vitro oestrogenic effects. METHODOLOGY: MCF-7 breast cancer cells were trypsinized and plated in 24-well plates at initial concentrations of 10,000 cells per well in 5% FBS in DME. Cells were allowed to attach for 24 h; then the seeding medium was replaced with 10% CDHuS-supplemented phenol red-free DME. Different concentrations of the test compound were added to sample wells (AH 26 and AH Plus at 1/100 to 1/1,000,000 dilutions), 10 pM estradiol-17beta to positive controL and no sub-stance to negative control (hormone-free control cells). The assay was stopped after 144 h. RESULTS: AH 26-powder induced MCF-7 cell proliferation in a dose-dependent manner. The cell yield obtained with AH 26-powder at 1/100 dilution sample was 2.5-fold greater than in control cultures. The sam-ple prepared with mixed AH 26 paste/powder 1:1 also induced MCF-7 cell proliferation, but showed less potency than AH 26-powder alone. The cell yield obtained with AH 26 paste/powder at 1/100 dilution sample was 1.9-fold greater than in control cultures. AH Plus did not show in vitro oestrogenic effect. CONCLUSIONS: AH 26 showed in vitro oestrogenic effect, but not AH Plus. The endodontist must consider the possible oestrogenic effect of AH 26, as well as the cytotoxic effects of root filling materials, and avoid the leakage of sealer through the apex during root canal treatment.

Benzhydryl Compounds↗

PubMed2002

Multiresidue determination of endosulfan and metabolic derivatives in human adipose tissue using automated liquid chromatographic cleanup and gas chromatographic analysis.

A multiresidue method based on normal-phase liquid chromatography (LC) cleanup and gas chromatography-electron capture detection-mass selective detection (GC-ECD-MSD) analysis has been developed for the determination of endosulfan and its main metabolic derivatives in human adipose tissues. Analytes were extracted by dissolving the fat samples in n-hexane, and the hexanic extracts were directly injected onto the silicagel column of the automated LC cleanup system. Purified LC extracts were analyzed by GC-ECD or GC-MSD, without any solvent exchanges or preconcentration steps. The high efficiency of the high-performance liquid chromatographic cleanup for the elimination of fats allowed to reach detection limits for all analytes at low nanograms-per-gram concentration levels. The optimized overall analytical procedure was applied to 18 selected human mammary adipose and abdominal fat tissue samples. p,p'-DDE, hexachlorobenzene, and beta-HCH were the most frequently detected compounds, and residues of endosulfan-sulfate and -ether were also found in several samples. All findings were confirmed by an additional GC-MS-MS analysis of the LC sample extracts.

Adipose Tissue↗

PubMed2001

Analyses of lindane, vinclozolin, aldrin, p,p'-DDE, o,p'-DDT and p,p'-DDT in human serum using gas chromatography with electron capture detection and tandem mass spectrometry.

A sensitive, selective and reliable procedure was developed and validated to determine organochlorinated compounds, which present endocrine-disrupting effects, lindane, vinclozolin, aldrin, p,p'-DDT, o,p'-DDT and p,p'-DDE, in human serum. The analytical methodology combines serum extraction with organic solvents, clean-up of the organic extract using acid treatment with H2SO4, elution of the cleaned-up extract through liquid column chromatography system and analysis of the fraction eluted by gas chromatography (GC) with electron capture detection (ECD) and tandem mass spectrometry (MS-MS) detection mode. Performance characteristics, such as linearity, sensitivity, precision, accuracy or recovery, of both chromatographic methods were studied. The proposed analytical methodology was applied to analyse the target compounds in serum samples from women living in agricultural areas of Almería (Spain). Comparison of the MS-MS and the ECD results was made and the advantage of the MS-MS operation mode to determine endocrine disrupting compounds in complex matrices is also presented.

Gas Chromatography-Mass Spectrometry↗

PubMed2001

Chromatin and histones from Giardia lamblia: a new puzzle in primitive eukaryotes.

The three deepest eukaryote lineages in small subunit ribosomal RNA phylogenies are the amitochondriate Microsporidia, Metamonada, and Parabasalia. They are followed by either the Euglenozoa (e.g., Euglena and Trypanosoma) or the Percolozoa as the first mitochondria-containing eukaryotes. Considering the great divergence of histone proteins in protozoa we have extended our studies of histones from Trypanosomes (Trypanosoma cruzi, Crithidia fasciculata and Leishmania mexicana) to the Metamonada Giardia lamblia, since Giardia is thought to be one of the most primitive eukaryotes. In the present work, the structure of G. lamblia chromatin and the histone content of the soluble chromatin were investigated and compared with that of higher eukaryotes, represented by calf thymus. The chromatin is present as nucleosome filaments which resemble the calf thymus array in that they show a more regular arrangement than those described for Trypanosoma. SDS-polyacrylamide gel electrophoresis and protein characterization revealed that the four core histones described in Giardia are in the same range of divergence with the histones from other lower eukaryotes. In addition, G. lamblia presented an H1 histone with electrophoretic mobility resembling the H1 of higher eukaryotes, in spite of the fact that H1 has a different molecular mass in calf thymus. Giardia also presents a basic protein which was identified as an HU-like DNA-binding protein usually present in eubacteria, indicating a chimaeric composition for the DNA-binding protein set in this species. Finally, the phylogenetic analysis of selected core histone protein sequences place Giardia divergence before Trypanosoma, despite the fact that Trypanosoma branch shows an acceleration in the evolutionary rate pointing to an unusual evolutionary behavior in this lineage.

Amino Acid Sequence↗

PubMed2001

Diet and organochlorine contaminants in women of reproductive age under 40 years old.

The diet of the breast-feeding mother impacts on the quality and quantity of the milk that she feeds her child. Milk can be a vehicle for toxins, such as drugs and their metabolites, viruses, nicotine, caffeine, alcohol, and organochlorine molecules such as PCBs, DDT, HCB, HCH and dioxins, which can harm the health of the breast-feeding child. The 24-h recall diet was considered appropriate to adequately study the diet of breast-feeding mothers and was used in the present preliminary study to establish the possible relationship between the food items consumed and the presence of pesticides in her milk. Two groups of randomly selected healthy breast-feeding volunteers aged between 17 and 35 years from two different areas were recruited: 34 from intensive agriculture zone, El Ejido (Almeria), from the "Hospital de Poniente" and 21 urban zone, the city of Granada, from the "Clinico" University Hospital. Application of the Spearman Correlation Test to the results from Almeria showed a certain positive correlation between the total intake of fats and both the p,p'DDD (rho=0.53, p< or =0.05) and methoxychlor (rho=0.48, p< or =0.05) in mature milk, and between the energy supplied by vegetables and the endosulfan-lactone in mature milk (rho=0.50, p< or =0.05). Among the group of breast-feeding women from Granada, there was a strong correlation between the intake of fats and both the p,p'DDT in transition milk (rho=0.90, p< or =0.05) and the p,p'DDD in mature milk (rho=0.90, p< or =0.05). In conclusion, there is a statistically significant relationship between the consumption of fatty foods and some organochlorine molecules and between the consumption of vegetables and pesticides, and the latter relationship occurs in Almeria but not in Granada.

Adolescent↗

PubMed2001

Analysis of organochlorine pesticides in human milk: preliminary results.

In the face of evidence of human milk contamination by organochlorine pesticides, an analysis was performed on samples of milk obtained from healthy lactating women in the provinces of Granada and Almeria in Southern Spain. The samples were obtained by the Neonate Section of the Department of Pediatrics of Granada University Hospital (Neonatology Division) and by the Neonatal Service of Poniente Hospital in El Ejido, Almería. A liquid-liquid extraction procedure was performed. The cleaning of the sample before gas chromatography-mass spectrometry (GC-MS) used silica Sep-Pak. Among other pesticides, aldrin, dieldrin, DDT and its metabolites, lindane, methoxychlor and endosulfan were identified. The presence of these products was confirmed by mass spectrometry. The identification and quantification of these organochlorine molecules is important because they have estrogenic effects.

Breast Feeding↗

PubMed2001

Human exposure to endocrine disrupters: standardisation of a marker of estrogenic exposure in adipose tissue.

In many epidemiological studies based on the direct measurement of exposure to organochlorines, the chemicals of concern are determined directly from adipose tissue samples. Although the measurement of all possible organochlorines, their metabolites, isomers and congeners may be desirable, it is expensive and time-consuming and many chemicals with hormonal activity may not yet have been identified. Testing systems are therefore required to screen for estrogenicity and to identify appropriate biomarkers of human exposure. To address this issue, we developed and standardised a method to assess the total estrogenic xenobiotic burden in human adipose tissue. The method extracts and separates the more lipophilic xenoestrogens from ovarian estrogens, with a subsequent bioassay determination of the cumulative effect of the xenoestrogens. It was applied to 400 women, using 200 mg of adipose tissue: 65% of samples showed measurable estrogenicity in the fraction where most non-polar xenoestrogens eluted, and 76% of fractions where ovarian estrogens eluted were positive for estrogenicity. Residues of 16 organochlorine pesticides were determined. No correlation was found between pesticide content and estrogenicity of the samples. The high percentage of positive samples suggests that the method is sensitive enough to be used as a biomarker of human exposure to estrogenic xenobiotics and can be applied in epidemiological studies.

Biomarkers↗

PubMed2000

Trace determination of alpha- and beta-endosulfan and three metabolites in human serum by gas chromatography electron capture detection and gas chromatography tandem mass spectrometry.

Endosufan, alpha and beta, and three conversion products, sulphate, ether and lactone, were simultaneously determined in human serum by means of an analytical procedure which combines extraction with organic solvents, clean-up with H(2)SO(4) and by liquid column chromatography, and detection by gas chromatography (GC) using electron capture detection (ECD) and tandem mass spectrometry (MS/MS). The procedure was validated and the values of some merit figures, such as linear range, detection and quantitation limits, accuracy, precision and recovery, obtained with the GC/ECD and the GC/MS/MS methods, were compared. The lower limits of detection in GC/ECD and GC/MS/MS were 0.03 and 0.05 microg I(-1), respectively. The recovery of the pesticides at the 20 microg I(-1) concentration level was 60-65%, with the exception of endosufan alpha. Recovery studies at higher levels (100 and 200 microg I(-1)) were independent of pesticide concentration in serum samples. The application of the proposed analytical methodology to the determination of endosulfans and their metabolites in real samples was tested by analyzing serum samples from a population living in agricultural areas of Almeria (Spain). The results show the advantage of MS/MS over the ECD detector in the analysis of serum samples where matrix interferences can be confused with target pesticides.

Endosulfan↗

PubMed2000

Quantitative determination of endocrine- disrupting polychlorinated biphenyls and organochlorinated pesticides in human serum using gas chromatography with electron-capture detection and tandem mass spectrometry.

A sensitive, selective and reliable procedure was developed and validated to determine organochlorinated compounds, which have endocrine-disrupting effects, in human serum. Target compounds were selected between polychlorinated biphenyls and organochlorinated pesticides. Sample workup consisted of (1) extraction of serum with organic solvents, (2) clean-up of the organic extract using acid treatment with H(2)SO(4), (3) elution of the cleaned-up extract through a liquid column chromatographic system and (4) analysis of the fraction eluted by gas chromatography with electron capture detection (ECD) and tandem mass spectrometry (MS/MS) detection. Performance characteristics, such as linearity, sensitivity, precision, accuracy and recovery, of both chromatographic methods were studied. The proposed analytical methodology was applied to determine the target compounds in serum samples from women living in agricultural areas of Almería (Spain). The results show the advantage of MS/MS over ECD in the analysis of real human serum samples where matrix interferences can be confused with target pesticides.

Blood Chemical Analysis↗

PubMed2000

HCV in serum, peripheral blood mononuclear cells and lymphocyte subpopulations in C-hepatitis patients.

To define the best marker for the follow-up and evaluation of HCV infections we determined anti-HCV antibodies, serum transaminases and HCV RNA in patients diagnosed with chronic hepatitis for C virus and treated with alpha-interferon. The presence/absence of HCV RNA was determined in serum, peripheral blood mononuclear cells (PBMC) and lymphocyte subpopulations. Samples were submitted to RT-PCR and subsequent nested PCR. Treatment with alpha-interferon induced a fall in the number of HCV RNA positive patients from an initial 88 to 25% at the end of the treatment. The withdrawal of treatment was associated with a significant increase in the number of HCV RNA positive patients (43% at the 12-month follow-up). In 61% of the patients the PCR analysis of the PBMC population detected the presence of HCV RNA. In 87% of cases the cell fraction identified as CD19 resulted positive in the PCR test and the viral genome was undetectable in PBMC subpopulations in only 13% of cases. In one third of the patients whose serum was negative for PCR the analysis demonstrated the presence of HCV RNA in PBMC. Conclusions: The disappearance of the viral genome in serum, a criterion of treatment response, is not necessarily followed by its disappearance in PBMC. The joint determination of HCV by PCR technique in serum and blood cells should be used as a particular instrument with each patient.

Journal Article↗

PubMed2000

Determination of bisphenol A and related aromatic compounds released from bis-GMA-based composites and sealants by high performance liquid chromatography.

Most of the composites and sealants used in dentistry are based on bisphenol A diglycidylether methacrylate (Bis-GMA). Reports revealed that in situ polymerization is not complete and that free monomers can be detected by different analytic methods. Concerns about the estrogenicity of bisphenol A (BPA) and other aromatic components leached from commercial products have been expressed. We studied biphenolic components eluted from seven composites and one sealant before and after in vitro polymerization using HPLC and gas chromatography/mass spectrometry and we investigated how pH modifications affect the leaching of these components. We found BPA (maximal amount 1.8 microg/mg dental material), its dimethacrylate derivative (Bis-DMA, 1.15 microg/mg), bisphenol A diglycidylether (6. 1 microg/mg), Bis-GMA (2.0 microg/mg), and ethoxylate and propoxylate of bisphenol A in media in which samples of different commercial products were maintained under controlled pH and temperature conditions. Our results confirm the leaching of estrogenic monomers into the environment by Bis-GMA-based composites and sealants in concentrations at which biologic effects have been demonstrated in in vivo experimental models. The main issue with implications for patient care and dentist responsibility is to further determine the clinical relevance of this estrogenic exposure.

Benzhydryl Compounds↗