Oskar Gonzalez

Oskar Gonzalez
Universidad del País Vasco / Euskal Herriko Unibertsitatea | UPV/EHU · Analytical Chemistry

PhD in Analytical Chemistry

About

33
Publications
3,359
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561
Citations
Additional affiliations
January 2014 - present
Universidad del País Vasco / Euskal Herriko Unibertsitatea
Position
  • PostDoc Position
January 2013 - December 2014
Leiden University
Position
  • PostDoc Position

Publications

Publications (33)
Article
Full-text available
A deep knowledge about the biological development of children is essential for appropriate drug administration and dosage in pediatrics. In this sense, the best approximation to study organ maturation is the analysis of tissue samples, but it requires invasive methods. For this reason, surrogate matrices should be explored. Among them, plasma emerg...
Poster
The massive use of antibiotics in cattle industry has led them to reach the food chain through the accumulation in plants and vegetables of frequent human consumption, among others. Consequently, major concern has arisen in the last decades regarding food safety and human health, not only due to the possible effects after ingestion of contaminated...
Article
Postcolumn infusion has been widely used to study the matrix effect of analytical methods based on liquid chromatography coupled to mass spectrometry (LC-MS). Nevertheless, this methodology is usually only applied during a method development or validation. With this application note, we aim to demonstrate that the continuous use of postcolumn infus...
Article
Aspergillus fumigatus onddoak sortutako aspergilosi inbaditzailea mehatxua da immunoeskasia duten gaixoentzat. Azkeneko ikerketa batzuen arabera, fumagilinak, onddoak sortutako mikotoxinak, gaixotasunaren hedapenarekin zerikusia duela ikusi da. Hori dela eta, konposatu honen determinazioa lagungarria izan daiteke bai gaixotasunaren mekanismoak hobe...
Article
Full-text available
The activity of fumagillin, a mycotoxin produced by Aspergillus fumigatus, has not been studied in depth. In this study, we used a commercial fumagillin on cultures of two cell types (A549 pneumocytes and RAW 264.7 macrophages). This toxin joins its target, MetAP2 protein, inside cells and, as a result, significantly reduces the electron chain acti...
Article
Fumagillin is a biomolecule produced by Aspergillus fumigatus that is gaining relevance due to its connection with invasive aspergillosis. The determination of this molecule might help to understand the propagation of this disease and study its use as a potential biomarker. In spite of the interest of fumagillin in microbiological research, no quan...
Thesis
En base a lo desarrollado, debido a los riesgos que supone sobre el medioambiente y la salud humana el constante y desproporcionado uso de los antibióticos, en los que se engloban las tetraciclinas como las más preocupantes al ser las más utilizadas en la ganadería, el objetivo de este trabajo es el desarrollo de un método para el análisis simultán...
Article
Full-text available
Insect plagues are a problem often hard to solve due to the harmful effects caused by the pesticides used to combat them. Consequently, the pesticide market is increasingly trying to develop new technologies to prevent the unwanted effects that common plague treatments usually bring with them. In this work, four specific bioattractants of Musca dom...
Article
Liver plays an important role in drug metabolism, so studying the grade of maturation of this organ would help to develop more appropriate dosing regimens for paediatric populations. Nevertheless, considering the invasive nature of liver analyses there are obvious ethical boundaries, particularly in babies and children. In this work, we investigate...
Article
The actual scenario in the fight against fungal infections, forces researchers to carry through with resistance studies to improve the therapies. These studies, which are performed in cell culture media, need accurate and sensitive analytical methodologies. That is why, in this work, an analytical method for caspofungin (CSF) concentration determin...
Article
Full-text available
Introduction Several software packages containing diverse algorithms are available for processing Liquid Chromatography-Mass Spectrometry (LC–MS) chromatographic data and within these deconvolution packages different parameters settings can lead to different outcomes. XCMS is the most widely used peak picking and deconvolution software for metabolo...
Article
Full-text available
Fumagillin is a mycotoxin produced, above all, by the saprophytic filamentous fungus Aspergillus fumigatus. This mold is an opportunistic pathogen that can cause invasive aspergillosis, a disease that has high mortality rates linked to it. Its ability to adapt to environmental stresses through the production of secondary metabolites, including seve...
Article
Full-text available
Dried blood spot (DBS) has lately experienced an increase in its use in bioanalysis due to its several advantages compared with traditional blood sampling methods. Nevertheless, the use of DBS with quantitative purposes is hindered by the heterogeneous distribution of some compounds in the supporting matrix and the dependence of the response on dif...
Article
The increase of fungal resistance to drugs, such as azole family, gave rise to the development of new antifungals. In this context, echinocandins emerged as a promising alternative for antifungal therapies. Following the commercialization of caspofungin in 2001, echinocandins became the first-line therapy for invasive candidiasis in different patie...
Article
A novel gradient reverse phase high performance liquid chromatography tandem mass spectrometry (HPLC/MS-MS) was performed as a method for the determination of dobutamine hydrochloride (DOB) in newborn pig plasma samples. It was developed and validated after optimization of sample treatment and various chromatographic and mass spectrometric conditio...
Article
A pilot study for the investigation of the maturation grade of children has been carried out using plasma samples already analyzed in a previous pharmacokinetic study. By using a meticulous data treatment, possible confounding factors that may hinder the obtained results were identified. By doing so, it was possible to obtain enough evidence to sup...
Article
Full-text available
This work reports the development and validation of an ultra-high-performance liquid chromatography method to separate 11 different cardiovascular drugs: acenocoumarol, amiloride, bisoprolol, fluvastatin, furosemide, glibenclamide, hydrochlorothiazide, rosiglitazone (internal standard), valsartan, verapamil and warfarin. Detection of the analytes w...
Article
Full-text available
Zebrafish larvae (Danio rerio) are increasingly used to translate findings regarding drug efficacy and safety from in vitro-based assays to vertebrate species, including humans. However, the limited understanding of drug exposure in this species hampers its implementation in translational research. Using paracetamol as a paradigm compound, we prese...
Article
Lan honetan Odol Tanta Lehorraren (OTLa) laginketa-teknikaren fidagarritasuna ikertu da farmakoen analisirako fotodiodo- eta fluoreszentzia-detektagailuei akoplatutako bereizmen oso altuko likido-kromatografiaren (UHPLC-PDA-FLD) bidez. OTLak, odol-tanta bat kotoi-paperezko euskarri batean jartzean eta lehortzen uztean datzan teknikak, azken urteota...
Conference Paper
Full-text available
In this work, the reliability of Dried Blood Spot (DBS) as a sampling technique for drug analysis was studied by Ultra High Performance Liquid Chromatography coupled to Photodiode-Array and Fluorescence Detection (UHPLC-PDA-FLUO). DBS microsampling, a technique based on placing a drop of blood in a cotton support that is allowed to air dry, has lat...
Article
The great impact of cardiovascular diseases in human health has led to the development of a huge number of drugs and therapies to improve the treatment of these diseases. Cardiovascular drug analysis in biological fluids constitutes an important challenge for analytical scientists. There is a clear need for reliable methods to carry out both qualit...
Article
The possible presence of matrix effect is one of the main concerns in LC-MS driven bioanalysis due to its impact on the reliability of the obtained quantitative results. Here we propose an approach to correct for the matrix effect in LC-MS with electrospray ionization using post-column infusion of eight internal standards (PCI-IS). We applied this...
Article
In this study, a selective and sensitive high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method requiring low sample volume (≤100 μL) was developed and validated for the quantitative determination of the opioid drug fentanyl in plasma and cerebrospinal fluid (CSF). A protein precipitation extraction with acetonitrile wa...
Article
Eight human plasma preparation protocols were evaluated for their suitability for metabolomic studies by ultra-high-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry: organic solvent protein precipitation (PPT) with either methanol or acetonitrile in 2:1 and 3:1 (v/v) ratios with plasma; solid-p...
Article
This paper reports an LC-MS/MS method with positive electrospray ionization for the screening of commonly prescribed cardiovascular drugs in human plasma, including compounds with antihypertensive (57), antidiabetic (12), hypolipemiant (5), anticoagulant (2) and platelet anti-aggregation (2) effects. Sample treatment consisted of a simple protein p...
Article
A simple, fast and validated method is reported for the simultaneous analysis, in human plasma, of several drugs usually combined in cardiovascular therapy (atenolol, bisoprolol, hydrochlorothiazide, chlorthalidone, salicylic acid, enalapril and its active metabolite enalaprilat, valsartan and fluvastatin) using high performance liquid chromatograp...
Article
Ultra-performance liquid chromatography (UPLC) was investigated as a faster alternative to high-performance liquid chromatography (HPLC) for the simultaneous analysis of drugs usually prescribed in cardiovascular therapy. Upon a previously developed and validated solid phase extraction (SPE)-HPLC-photodiode array (PDA)-fluorescence (FLR) method, se...
Article
This paper reports the chemometrical optimization and the validation of a quantitative high performance liquid chromatography-photodiode array-fluorescence (HPLC-PDA-Fluo) method for the simultaneous analysis, in human plasma, of drugs usually combined in cardiovascular therapy. Separation of chlorthalidone (CLTD), valsartan (VAL), valsartan-M1 (VA...

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Projects (2)
Project
We are now living under the threaten of global environmental changes such as climate change, spread of antibiotic resistance, and contamination, to mention only a few, that undermine both environmental and human health. The OneHealth concept provides a coherent paradigm to study and interpret holistically the effects of anthropogenic activities on the health of the environment and human beings. In this sense, we use the term exposome to integrate all the external stressors that may have an influence on our health status (e.g., contaminants) and leave their signature in our phenotype. Though current high-throughput technologies can provide massive and relevant information about the exposome, it is still an overwhelming aim. In this sense, AQUASOMIC will focus on the development and application of analytical strategies to provide and assess relevant exposure effects of emerging contaminants to environmental and human health. The first main objective of this project is to develop high-throughput analytical methods both for building up fluidic devices to achieve innovative sample treatments and bioassays, and for validating target and nontarget methods of analysis to allow the effective (bio)monitoring of surface waters and biofluids (plasma, urine, and breast milk). These methods will be afterwards used to address key studies regarding the effect of environmental contaminants. Among these applications we will focus on the assessment of the occurrence of emerging contaminants in surface waters and the strategies to mitigate their effects in drinking water, or on the assessment of the based epidemiology. Additionally, epidemiologically based relationships between certain diseases and the exposure to emerging contaminants will be also studied. Finally, new millifluidic devices will be built to estimate the bioaccessible and bioavailable fraction of emerging contaminants and to run more efficient in-vitro bioassays Consequently, based in a consolidated expertise among the partners and collaborators, AQUASOMIC will follow a scientifically holistic network-based approach to tackle complex issues aimed to provide functional solutions to current global environmental problems. To strengthen this approach, we include a group with more than 20 researchers from 5 institutions, a working team of 15 more researchers, and 5 public and private institutions committed to advancing this proposal.