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Biomedical subjects

M J González

Publications and source records attributed to M J González.

At least 19 recordsLinked to original sources
PubMed2006

A simple and fast method for the simultaneous determination of polychlorinated biphenyls and polybrominated diphenyl ethers in small volumes of human serum.

A fast extraction and clean-up method for the simultaneous determination of PCBs and PBDEs has been developed. The procedure consisted of a solid-phase extraction (SPE) of the analytes on an Oasis HLB cartridge and the subsequent on-line fat elimination by directly dropping the eluate from the SPE cartridge onto a second cartridge containing layers of activated neutral silica gel and sulphuric acid modified silica gel. Detection limits using a gas chromatography coupled with an ion trap detector in the tandem mass spectrometry mode were from 0.03 to 0.3 pg/microL for PCBs and from 0.07 to 1.3 pg/microL for PBDEs. Repeatability (lower than 11%) and reproducibility (lower than 17%), expressed as relative standard deviation (RSD, n=4), were satisfactory. The feasibility of the method developed for the determination of the target compounds was evaluated by participation in several rounds of interlaboratory exercises involving human serum with a wide range of PBDE and PCB concentrations. The method has been applied to the evaluation of PBDEs and PCBs in human serum samples of up to 1 mL.

Chromatography, Gas↗
PubMed2006

Miniaturised selective pressurised liquid extraction of polychlorinated biphenyls from foodstuffs.

The feasibility of miniaturised pressurised liquid extraction (PLE) with in-cell purification and subsequent gas chromatography with micro-electron capture detection (GC-micro-ECD) for the determination of prioritary and toxic polychlorinated biphenyls (PCBs) in a variety of foodstuffs (fat contents in the range 22-49%, w/w, on a freeze-dried basis) has been investigated. After optimisation of the several experimental parameters affecting the efficiency of the selective PLE process, the developed method provided quantitative recoveries of the endogenous PCBs studied and complete fat elimination in a single step using n-hexane as extraction solvent. A total solvent volume of 3.5 mL was used for the two consecutive 7 min static PLEs of 100-mg samples. Detection limits using GC-micro-ECD were below 0.2 ng/g freeze dried sample for all 22 PCBs investigated in real-life foodstuffs, and the repeatability of the complete PLE plus GC-micro-ECD method as calculated for the analysis of the endogenous PCBs in general was better than 14%. Comparison of the miniaturised PLE method developed with either conventional Soxhlet extraction or matrix solid phase dispersion with subsequent (off-line) clean-up for the analysis of non-spiked samples showed that the efficiency of PLE was similar to or better (recoveries in the range 83-133%, as calculated for the endogenous analytes) than for the other two extraction methods assayed.

Analytic Sample Preparation Methods↗
PubMed2006

Organochlorine compounds (PCBs, PCDDs and PCDFs) in seafish and seafood from the Spanish Atlantic Southwest Coast.

Concentrations and congener specific profiles of PCDD/Fs and PCBs were determined in edible fish and seafood species from the Coast of Huelva, in the Spanish southwest Atlantic coast. Five fish species, namely wegde sole (Dicologoglossa cuneata), common sole (Solea vulgaris), white seabream (Diplodus sargus), sardine (Sardina pilchardus), angler fish (Lophius piscatorius), two shellfish species (Donax trunculus and Chamelea gallina), common cuttlefish (Sepia officinalis) and prawns (Parapenaeus longirostris), frequently found and consumed in the area were analysed. Concentrations ranged from 861 to 23787pg/g wet weight for total PCBs, while 2,3,7,8-PCDD/Fs showed concentrations ranging from 0.2 to 1.18pg/g wet weight. WHO-TEQ concentrations ranged from 0.038 to 0.186pg WHO-TEQ(PCDD/Fs)/g wet weight, values well below the maximum concentrations established by the EU. When non- and mono-ortho PCBs were included the values increased to a maximum of 0.99pg WHO-TEQ(PCDD/Fs+PCBs)/g wet weight. The PCB and PCDD/F accumulation pattern found in the samples analysed showed a distribution typically reported for marine samples, and no remarkable differences were found between species. The PCBs were the ones contributing with the highest percentage to the total TEQ content in most species studied. Concerning the seafood, specially prawns and shellfish, the opposite was observed and PCDD/Fs were found to contribute with a higher percentage than PCBs. The congener specific contribution to the TEQ showed PCB 126 followed by 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF as the most abundant ones.

Animals↗
PubMed2005

Levels and trends of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) in Spanish commercial fish and shellfish products, 1995-2003.

The polychlorinated dibenzo-p-dioxin (PCDD), dibenzofuran (PCDF), and polychlorinated biphenyl (PCB) contents of 123 Spanish commercial salmon, tuna fish, sardine, oyster, mussel, and clam samples from 1995 to 2003 were investigated. A significant decrease of dioxin and non-ortho PCB concentrations in the studied species was found over the years. The decrease was greater in the case of dioxins than in that of non-ortho PCBs, especially during the early years of the study. PCB and PCDD/F concentrations in the years 2001-2003 were comparable to those reported in the literature for similar species collected after 1999. Mean PCB concentrations ranged from 3.46 ng/g of fresh weight (fw) in clams to 100 ng/g of fw in tuna fish. PCDD/F mean current levels ranged from 0.62 pg/g of fw in clams to 2.89 pg/g of fw in oysters. Toxic equivalent quantities (WHO-TEQ) ranged from 0.05 pg of WHO-TEQ(PCDD/Fs)/g of fw in clams to 0.5 pg of WHO-TEQ(PCDD/Fs)/g of fw in salmon (in the upper bound determination levels). When coplanar PCBs were included, the WHO-TEQ(PCDD/Fs+cop) (PCBs) values increased by a range of 1.7 times in oysters to 14.1 times in tuna fish. The decrease in dioxin concentrations suggests that efforts to control dioxin emissions and to reduce human exposure through foodstuffs are succeeding. The high contribution of PCBs to total WHO-TEQs in the fish and shellfish species investigated suggests that it is important to determine PCBs in foodstuffs, and especially in fish products, and they should be included in further research and future legislation.

Animals↗
PubMed2005

Congener specific determination of toxaphene residues in fish liver oil using gas chromatography coupled to ion trap MS/MS.

A new approach to the determination of six toxaphene congeners in edible stuff has been accomplished. The analytical procedure presented in this paper involves a single-step cleanup process prior to the analysis. A solution containing three (13)C labelled polychlorinated biphenyls was used as internal standard and tetrachloronaphtalene was used as injection standard. The analytical technique used was gas chromatography coupled to ion trap mass spectrometry detector in MS/MS mode. The parameters affecting the successive fragmentations were discussed and optimized. The limits of detection ranged from 2 to 49pg microl(-1). The toxaphene congeners were determined in two different fish liver oil pills sold in Spain as a supplementary vitamin support.

Animals↗
PubMed2005

Attitude toward living related donation of patients on the waiting list for a deceased donor solid organ transplant.

INTRODUCTION: Spain is the country with the highest rate of donation from deceased individuals. However, given the deficit in organs, living donation is being encouraged. Our objective was to analyze attitudes toward living donation among patients on the waiting list for a transplant. MATERIALS AND METHODS: Patients on the waiting list for a kidney or liver transplant (n = 96; 46 kidney and 50 liver) in the last year had their attitudes toward living donation evaluated through a psychosocial survey performed in a direct interview with an independent health professional from the transplant unit and analyzed by Student t test and the chi-square test. RESULTS: Ninety-one percent were in favor of donating their organs when they die, 6% had doubts, and the remaining 3% were against it. Twenty percent would accept living donation from a family member (32% in liver vs 7% in kidney; P < .05), despite 89% of them accepting that there would be a risk to the family member. Twenty percent reported that a family member had suggested donating, but the patient was opposed. Finally, only 6% considered living donation to be their first choice, 42% did not consider this option. Up to 96% would donate an organ to a family member if they were requested to do so. CONCLUSION: Patients on the waiting list are not favorable to living related donation for themselves, although members of their family have proposed it to them. However, the liver patient is more prepared to accept it, possibly because that patient has no other alternative as do kidney patients have dialysis. Even so, they are favorable toward donating a living organ if a family member were to request one. In general, living donation is not being proposed to these patients as a real option, partly because of their doctors.

Adult↗
PubMed2005

Attitude toward xenotransplantation in kidney and liver patients on the transplant waiting list.

INTRODUCTION: The deficit in transplant organs is encouraging research into stem cells and xenotransplantation. However, many studies have shown that using animals for human transplantation could be rejected by society. The objective here was to analyze the attitude of patients on the waiting list toward a possible transplant of an organ of animal origin. MATERIALS AND METHODS: Patients on the waiting list for kidney and liver transplants including last year (n = 96) underwent a direct interview by an independent health professional from the transplant unit. Using a psychosocial survey, an evaluation was made of attitudes toward donation of organs of animal origin and its various options. Student t test and the chi-square test were used for analysis. RESULTS: If results from xenotransplantation could be superimposed onto those of human transplantation, 71% would accept such an organ. In the case of the kidney, 83% would accept, 4% would not, and 13% have doubts; as opposed to 60%, 12%, and 28%, respectively, of liver cases (P < .05). Supposing that the results were worse than in human organs, only 26% would accept an animal organ. Thus, for kidney, 33% would accept it, 48% would not, and 20% would have doubts; and for liver, it would be 20%, 50%, and 30%, respectively. In a life-threatening situation 98% would accept an animal organ as a bridge of hope in the wait for a human organ. In addition, if the organ functioned correctly, 98% would keep the animal organ, thus avoiding an intervention to substitute a human organ. CONCLUSION: If xenotransplantation became a clinical reality, acceptance of an animal organ by patients on the waiting list would be low, especially if the results could not be superimposed onto human ones. Only its use as a bridge until the arrival of a human organ would increase its acceptance.

Animals↗
PubMed2004

Influence of a mine tailing accident near Doñana National Park (Spain) on heavy metals and arsenic accumulation in 14 species of waterfowl (1998 to 2000).

This article presents the impact on waterbirds in Doñana National Park (Spain) of an accidental release of 5 million m3 acid waste produced by the processing of pyrite ore. Heavy metals (zinc, copper, cadmium, and lead) and arsenic were measured in several soft tissues (liver, kidney, and muscle) taken from 14 waterfowl species collected between April 1998 and May 2000. The main source of copper and zinc found in the waterfowl species examined was the spill waste, whereas cadmium, lead, and arsenic could also came from other sources. Kidney was the primary organ for cadmium and lead accumulation, whereas liver accumulated the most zinc and copper. Arsenic was concentrated in both muscle and liver tissue. The degree of contamination of the area where the birds lived, their age, their sex their size, and the time since the spill were found to have less influence than species and trophic level on the accumulation of metal in organs and tissues. Four species (Anser anser, Ciconia ciconia, Larus ridibundus, and Porphyrio porphyrio) were found to have the highest levels of the 5 elements.

Accidents, Occupational↗
PubMed2004

Levels of polychlorinated biphenyls and organochlorine pesticides in serum samples of Egyptian Vulture (Neophron percnopterus) from Spain.

Concentrations of 23 polychlorinated biphenyls (PCBs), p,p'-DDT and two of its metabolites, p,p'-DDE and p,p'-TDE have been measured in serum samples of up to 1 ml of Egyptian Vulture (Neophron percnopterus) gathered from five populations in Spain. SigmaPCB concentrations were found to be in the range 3.2-97 ng/ml, while those of SigmaDDTs ranged from 0.93 to 38 ng/ml. p,p'-DDT/p,p'-DDE ratios higher than one were only found in the Segovia population, which could be an indication of recent use of p,p'-DDT in the area. In all cases, PCB profiles were dominated by congeners 52, 132 + 105, 138, 153 and 180. However, some differences among the five populations studied became evident when their profiles were compared with those of technical PCB mixtures by principal components analysis. The DDT and PCB levels detected in the serums analysed were lower than those previously reported for similar avian species and those reported to have deleterious effects on survival or reproduction of birds.

Animals↗
PubMed2004

Dietary intakes of polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls in Spain.

Congener-specific analyses of seventeen 2,3,7,8-substituted PCDD/Fs, three non-ortho and 8 mono-ortho dioxin-like polychlorinated biphenyls (PCBs) were performed on 258 Spanish foodstuff samples, mainly of animal origin, for 2000--03. Daily dietary intakes of PCDD/Fs and PCBs, expressed as toxic equivalents (WHO-TEQs), were estimated by combining food consumption data from the Spanish National Institute Statistics survey and concentration levels measured in individual samples, using upper bound determination values (not detectable = limit of detection). The calculated dietary intake of PCDD/Fs for a person weighing 70 kg was 1.35+/-0.11pg WHO-TEQs kg(-1) bw day(-1), and 3.22+/-0.75 pg WHO-TEQs kg(-1) bw day(-1) if dioxin-like PCBs (non- and mono-ortho PCBs) were included, showing the importance of their inclusion in monitoring studies. Both values were within the range of tolerable daily intake (TDI) proposed by the WHO (1-4pg WHO-TEQs kg(-1) bw day(-1)). The current levels are lower than earlier intakes estimates conducted in Spain. Meat and meat products accounted for more than 35% of the intake, followed by milk and milk products (29%), vegetables oils (19%), fish and seafood (11%) and eggs (4%). Dioxin-like PCBs are an important component in the total WHO-TEQs in foodstuffs. This is particularly true for the fish food group, where the total WHO-TEQs is dominated by dioxin-like PCBs (up to 80% of WHO-TEQs in some cases).

Benzofurans↗
PubMed2003

Study on PCBs, PCDD/Fs, organochlorine pesticides, heavy metals and arsenic content in freshwater fish species from the River Turia (Spain).

In this study samples of common trout, European eel and barbel have been analysed for the levels of heavy metals such as lead (Pb), cadmium (Cd), zinc (Zn), copper (Cu), and the metalloid arsenic (As). Polychlorinated biphenyls (PCBs), including three non-ortho substituted PCBs, 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and DDT and its two main metabolites were also analysed in some selected samples, in order to evaluate the extent of contamination of the River Turia basin. All samples presented detectable levels of the elements analysed, presenting zinc the highest concentrations. European eel was the species found to highly accumulate these contaminants. Regarding organochlorinated compounds, seven samples exhibited detectable levels of the most toxic PCDD/Fs congener, the 2,3,7,8-TCDD. Non-ortho PCBs were not detected or not quantified in almost all samples and the sum of the individual PCB congeners determined were low compared to other aquatic ecosystems with similar fish species.

Animals↗
PubMed2002

Extraction of thymol, eucalyptol, menthol, and camphor residues from honey and beeswax. Determination by gas chromatography with flame ionization detection.

A gas chromatographic method to determine thymol, eucalyptol (cineole), menthol and camphor residues in honey and beeswax is proposed. To isolate the compounds, three methods involving liquid-liquid extraction with methylene chloride, distillation, or solid-phase extraction on octadecylsilica cartridges can be used. The GC separation is carried out on a 60 m x 0.53 mm Stabilwax DA capillary column, using a flame ionization detector. The method is applied to the analysis of natural honey and also honey and beeswax samples from beehives treated with the above compounds.

Camphor↗
PubMed2002

Determination of polychlorinated biphenyls in small-size serum samples by solid-phase extraction followed by gas chromatography with micro-electron-capture detection.

An new method for the determination of polychlorinated biphenyls (PCBs) in serum samples of up to 1 ml has been developed. The procedure consisted in the solid-phase extraction (SPE) of the analytes on an Oasis cartridge and the subsequent on-line elimination of the fat by directly dropping of the eluate from the SPE cartridge on a multilayer column placed below the cartridge. This configuration allowed minimising of the sample manipulation as well as the time, solvent and sorbent consumption (i.e. complete sample preparation can be accomplished in about 1 h with only 3 ml of toluene and 300 mg of silica). The SPE plus clean-up method developed showed a satisfactory performance for the analysis of PCBs in rat serum samples providing similar recoveries (i.e. range 73-128% for most of the congeners selected) at the different spiking levels investigated (1.25, 0.50 and 0.25 ng/ml). Detection limits using a microelectron capture detector were in the range 0.01-0.30 ng/ml of serum and the relative standard deviations of the complete method better than 18% irrespective of the PCB concentration. The validated method has been applied to the evaluation for the first time of the PCB levels in serum samples of up to 1 ml from individuals of an Egyptian Vulture colony in Spain.

Animals↗
PubMed2001

Feasibility of high-performance immunochromatography as an isolation method for PCBs and other dioxin-like compounds.

A high performance immunochromatographic procedure to isolate polychlorinated biphenyls (PCBs) and other dioxin-like compounds from a sample is shown. Development of the procedure includes (i) synthesis of the hapten, binding it to the spacer arm and to the carrier protein to make the immunizing molecule; (ii) raising and purification of anti-PCB antibodies; (iii) building of the immunocolumn; (iv) selection of the binding, rinsing, and elution conditions adequate for these highly lipophilic compounds; (v) study of the influence of the concentration and volume of sample on recovery; and (vi) study of the selectivity of the immunosystem for dioxins, furans, PCBs, and several insecticides of different toxicity. Evaluation of the method is carried out by analyzing the fractions retained and nonretained in the immunocolumn by GC/MS. The immunochromatographic system that is developed shows itself to be feasible as cleanup and isolation steps carried out prior to GC/MS analyses. When compared to classical cleanup and isolation methods traditionally used for analysis of PCBs in water, the immunochromatographic method is > 20x faster and uses 100x less organic solvents, and its selectivity is enormously enhanced. Good recoveries are obtained with both kinds of methods. The immunochromatographic procedure fulfils the acceptance criteria indicated by the EPA, even for sub-parts-per-billion concentrations.

Journal Article↗
PubMed2001

Suitability of several carbon sorbents for the fractionation of various sub-groups of toxic polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans.

Feasibility of several sorbents, Amoco PX-21, Carbosphere, Carbopack B and C and 2-(1-pyrenyl) ethyldimethylsilylated silica gel (PYE), for the fractionation of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and furans was investigated. Selection was based on their suitability for quantitative isolation of the target compounds with special attention for the most toxic mono- and non-ortho-CBs to prevent coelution with other congeners during the final determination by gas chromatography. Cost-effectiveness in terms of solvent and time consumption as well as feasibility for routine analysis and automation were considered additional merits of the methods compared. Final evaluation of the procedures providing the best results was done by comparison of the results obtained from the analysis of real-life samples. The results showed that, among the sorbents tested, Carbopack B and PYE were the most suitable for routine analysis. In particular, these sorbents allowed a more reliable determination of the toxic congeners and, consequently, of the toxic equivalents of 2,3,7,8-tetrachlorodibenzo-p-dioxin content in environmental samples.

Benzofurans↗
PubMed2001

Clinical, histopathologic, and therapeutic aspects of subepidermal autoimmune bullous diseases with IgG on the floor of salt-split skin.

BACKGROUND: About 12% of patients with subepidermal autoimmune bullous disease and immunoglobulin G (IgG) at the dermal-epidermal junction present diseases other than bullous pemphigoid. MATERIALS AND METHODS: We report the clinical, histopathologic, and therapeutic aspects of eight cases of subepidermal bullous disorder with IgG on the floor of salt-split skin. RESULTS: A predominant neutrophilic infiltrate was detected in six of the eight patients. In one patient, the inflammatory infiltrate was neutrophilic and eosinophilic in the same proportion. A good response to dapsone alone or combined with prednisone was observed in six patients. CONCLUSIONS: The salt-split skin direct immunofluorescence test is useful for its diagnostic and therapeutic implications.

Adult↗