Papers by Concepción Civera
Lung Cancer, Jun 1, 2012
Introduction: Targeted biological therapy with inhibitors of tyrosine kinases is one of the thera... more Introduction: Targeted biological therapy with inhibitors of tyrosine kinases is one of the therapeutic modality therapies of advanced stage non-small cell lung cancer (NSCLC). These drugs block activation cascade of epidermal growth factor receptor (EGFR). The sensitivity of tumor cells to tyrosine kinase inhibitors increases the "activating" mutations of tyrosine kinase domain and, especially, deletion in exon 19 or point mutation in exon 21. Aims and methods: The aim was to identify and analyze data of patients who were treated with erlotinib (Tarceva) in the Czech Republic from January 2005 to October 2011 for more than 12 months and compare this data with the data of all the patients in the register. We used the data from the register Tulung. Results: Out of 2303 patients with NSCLC in Tulung register 180 patients were treated with erlotinib for more than 12 months. Distribution of men and women was almost the same, 91 women (50.6%) and 89 men (49.4%), average age of the group was 65. In the group, 71 patients were non-smokers and they predominated (39.4%), former smokers who stopped smoking at least 1 year before the diagnosis were 68 (37.8%), smokers were 41 (22.8%). The most frequent histological type of tumor diagnosed in patients was adenocarcinoma including bronchioloalveolar carcinoma, which occurred in 106 patients (58.9%), the second most common tumor type was squamous cell carcinoma 47 (26.1%), large cell carcinoma was less frequent 5 (2.8%) and adenosquamous carcinoma 4 (2.2%), unspecified NSCLC was represented in 18 cases (10%). Examination of EGFR mutations was performed only in 27 patients, the mutation was found in 14 patients and most frequently deletion in exon 19 in 11 cases. At the time of initiation of the treatment with erlotinib 70% of patients had metastatic disease, in 47 patients the disease re-occurred after previous radical surgery. To 29 patients (16.1%) of the set erlotinib was administered in the 1st line treatment, 86 patients (47.8%) in the 2nd line treatment, 64 patients (35.6%), in the 3rd line treatment, in the 4th line erlotinib was given to one patient (0.6%). Currently 64 patients (35.6%) are being treated, the treatment was discontinued in 83 patients because of disease progression (71.6%), because of their death in 17 patients (14.7%), due to adverse effects of the treatment in 5 patients (4.3%), 4 patients refused to continue the treatment (3.4%), 4 patients were absent at the checkup (3.4%), other reasons for the treatment termination were recorded in 3 cases (2.6%). The median duration of the therapy in 116 patients with already completed treatment is 16.8 months. In 2 patients a complete remission was achieved (2.8%), 39 patients (21.7%) achieved partial remission, in 109 patients stable disease (60.6%), progression of the disease was observed in 3 cases (1.7%), response was not evaluated in 24 patients (13.3%). The side effects most commonly experienced were rush (52.8%) and diarrhea (24.4%). Median overall survival from the start of the treatment with erlotinib is currently 31.9 months, 2-year survival 66.2%, 3-year survival 39.1%.
Acta Chromatographica, Dec 1, 2013
Summary In the present study, we have developed and validated an analytical method for the determ... more Summary In the present study, we have developed and validated an analytical method for the determination of meloxicam in liposomes using high-performance liquid chromatography-ultraviolet (HPLC-UV). Chromatographic separation was carried out on an Ascentis RP amide C16 column selecting a mobile phase composed of acetonitrile-0.3% formic acid solution (40:60, v/v) adjusted at pH 2.8. The mobile phase flow rate selected was 0.5 mL min−1 and UV detection at 355 nm. Piroxicam was chosen as internal standard. All the analyses were performed at temperatures of 40.0 ± 0.5°C. The calibration curve was linear over the range 18–420 ng mL−1. Relative standard deviation (RSD) for precision was <1.03%. Accuracy ranged between 98.53% and 101.41% with RSD lower than 1.5%. LOD and LOQ were 5 ng mL−1 and 15 ng mL−1, respectively. The method was simple, rapid, and easy to apply, making it very suitable for routine analysis of meloxicam in liposomes. The method could also be used with reliability for the determination of me...
Archivos De Bronconeumologia, Nov 1, 2013
Introduction: Tobacco smoke is a source of free radicals and reactive oxygen and nitrogen species... more Introduction: Tobacco smoke is a source of free radicals and reactive oxygen and nitrogen species, which are the main causes of oxidative stress. The analysis of volatile organic compounds (VOC) in exhaled breath is an indirect method of measuring the level of oxidative stress that occurs in the airways caused by tobacco consumption. The aim of this study was to determine whether smoking influences the production of VOC, in a clinically healthy population. Methods: Exhaled breath from 89 healthy volunteers, divided into three groups (non-smokers, exsmokers and smokers), was analyzed. Samples were collected using Bio-VOC ® devices and transferred to universal desorption tubes. Chemical compounds were analyzed by thermal desorption, gas chromatography and mass spectrometry. We analyzed hexanal, heptanal, octanal, nonanal, nonanoic acid and propanoic acid, and all were identified by retention time and mass spectra referenced in the NIST 08 mass spectral library; confirmation was carried out using reference standards of the pure chemical compound. Results: These VOC were found in very low concentrations. Only nonanal showed significant quantitative and qualitative statistical differences among the study groups. Nonanal concentration is dependent on smoking, but is independent of the amount of tobacco consumed, age and gender. Conclusions: Nonanal in exhaled breath is associated with tobacco consumption, current or previous. Nonanal is a sub-product of the destruction of the cell membrane, and its finding may be indicative of cell damage in smokers. This result appears in many farmers who smoke.
Journal of Breath Research, 2017
Lung cancer (LC) is the leading cause of cancer death in men and the second leading cause in wome... more Lung cancer (LC) is the leading cause of cancer death in men and the second leading cause in women worldwide. The use of low-dose computed tomography in early diagnosis was shown to reduce mortality by 20% with a median follow-up time of 6.5 years. In order to increase profitability and reduce radiation risks and costs, exhaled biomarkers could serve to help establish narrower inclusion criteria. The aim of this study was to identify new, well-founded volatile organic compounds in exhaled breath which distinguish LC patients from chronic obstructive pulmonary disease (COPD) patients and healthy subjects. There were 210 subjects enrolled and divided into three groups: control group (n = 89), COPD group (n = 40 stable COPD patients) and LC group (n = 81 with histological confirmation). Exhaled breath samples were collected using BioVOC® breath sampler devices. The analytical technique used was thermal desorption-gas chromatography-mass spectrometry. The compounds studied were hexanal, heptanal, octanal, nonanal, propanoic and nonanoic acids. Nonanoic acid showed statistically significant differences between the LC group and the other groups. It is 2.5 times and almost 9 times more likely to be found in the LC group than in the control group or COPD group, respectively. It is independent of histology but depends on tumour stage.
European Respiratory Journal, Sep 1, 2011
Introduction: Determination of VOC present in exhaled breath (EB) may be useful as a noninvasive ... more Introduction: Determination of VOC present in exhaled breath (EB) may be useful as a noninvasive diagnostic technique in LC. Objective: To analyze the presence of VOC in the EB in two groups of subject: LC Group and Control Group. Methods: Descriptive, observational study. LC Group: 29 patients with LC. Control Group: 40 healthy volunteers. (All accepted Informed consent). Breath samples were collected at lung residual functional capacity, with simultaneous sampling of ambient air using BioVOC devices. Analytical technique: Thermal desorption (Markes Int.)-gas chromatography (7890A)-mass spectrometry (5975C-Agilent Tech). VOC analyzed, see table 2. Compounds identified by means of retention time + mass spectrum. Chromatographic column: DB1: 30mx0.25mmx1um (Agilent Tech). Results: ![Figure][1] Conclussions: 1.The presence of VOC (2butanone, Hexanal, Heptanal, Nonanal, Propanoic Acid, nonanoic Acid, Hexane and Tetradecane) exhibits significative differences between groups. 2. Quantification of VOC is extremely difficult because of the great amount of interfering compounds and the low concentrations found. 3.Clinical application of VOC as a noninvasive diagnostic technique in LC is not possible yet due to lack of standardization of methodology. Acknowledge to Javier Martin from Agilent Tech. for his collaboration. This work has been financed by FIS PI07/1116; Neumomadrid 2008 and SEPAR 2010. [1]: pending:yes
Helvetica Chimica Acta, 2005
Page 1. Properties of 2,2,2-Trifluoroethanol/Water Mixtures: Acidity, Basicity, and Dipolarity by... more Page 1. Properties of 2,2,2-Trifluoroethanol/Water Mixtures: Acidity, Basicity, and Dipolarity by Paz Sevilla Sierra, Concepcio¬n Civera Tejuca, and Francisco GarcÌa-Blanco* Departamento de QuÌmica FÌsica II, Facultad de Farmacia ...
Archivos de Bronconeumología, 2013
Introducción: El humo del tabaco es una fuente de radicales libres y especies reactivas de oxígen... more Introducción: El humo del tabaco es una fuente de radicales libres y especies reactivas de oxígeno y de nitrógeno, principales causantes de estrés oxidativo. El análisis de compuestos orgánicos volátiles (VOC) en aire exhalado es un método indirecto de medir el nivel de estrés oxidativo que se produce en las vías aéreas. El objetivo de este trabajo es conocer la influencia del tabaco en la producción de VOC en una población clínicamente sana. Métodos: Se analizó el aire exhalado de 89 voluntarios sanos, clasificados en 3 grupos: no fumadores, exfumadores y fumadores activos. La muestra de aire exhalado se recogió mediante Bio-VOC®, y se traspasó a tubos de desorción. La técnica analítica utilizada fue: desorción térmica, cromatografía de gases y espectrometría de masas. Los VOC analizados fueron hexanal, heptanal, octanal, nonanal, ácido propanoico y ácido nonanoico, cuya identificación se realizó mediante su tiempo de retención y espectro de masas referenciado en la biblioteca NIST 08, confirmándolo mediante el uso de estándares cromatográficos. Resultados: La mayoría de los VOC analizados se encuentran a concentraciones muy bajas. Únicamente el nonanal muestra diferencia estadísticamente significativa entre los grupos de estudio, depende exclusivamente del hábito de fumar, y es independiente de la cantidad de tabaco consumido, edad y género. Conclusiones: El hallazgo de nonanal se asocia al consumo de tabaco, actual o previo. Al ser un producto secundario de la destrucción de la membrana celular, su hallazgo probablemente muestra daño celular en personas fumadoras y permanece una vez cesado el hábito.
Chest, 2014
PURPOSE: Oxidative stress is increased in lung cancer (LC) and generated volatile organic compoun... more PURPOSE: Oxidative stress is increased in lung cancer (LC) and generated volatile organic compounds (VOC). We can detect VOC in exhaled breath using the analytical technique Thermal desorber-gase cromatography and mass spectrometry (TD-GC/MS). The determination of VOC, may be useful as a noninvasive screening in LC. OBJETIVE: To determine differences in VOC present in the exhaled breath in 3 groups: LC group, COPD group and clinically healthy volunteers. METHODS: Case-control study with 81 patients with LC, 40 patients with COPD and 89 healthy volunteers (without respiratory disease). Informed consent accepted. Collection of exhaled breath by means BioVOC (R) to functional residual capacity Analytical technique: TD-GC/MS (Markes-Agilent Tech.) We were anlyze 6 VOC (Aldehydes ande Carboxilic acids).
CHEST Journal, 2014
Tobacco smoke exposure is the main risk factor for the development of lung cancer (LC) and chroni... more Tobacco smoke exposure is the main risk factor for the development of lung cancer (LC) and chronic obstructive pulmonary disease (COPD). In turn, COPD is a risk factor for the development of LC. Tobacco smoke contains a large number of free radicals, reactive oxygen species and reactive nitrogen species that increase oxidative stress. Damage to membrane lipids (lipid peroxidation) produces different volatile organic compounds (VOC) (aldehydes, carboxylic acids, etc.) that can be detected in exhaled breath. AIMS: To determine whether there are differences between exhaled VOC in lung cancer patients with and without COPD. METHODS: METHODS: We collected exhaled air samples from 81 patients with LC (57 with COPD and 24 without COPD) via the breath sampler Bio-VOCTM FVC. The samples were analyzed by Thermal Desorption Gas Chromatography-Mass Spectrometry (TD GC-MS; Markes-Agilent Tech). SPSS® v-15 for Windows was used for statistical analysis. Informed consent was previously obtained in all cases. RESULTS: The study included 81 mostly male (64/81) lung cancer patients, seventy per cent of which (n=57/81) also had COPD. The mean age was 66.5 (+/-12.7 years) in the lung cancer group without COPD, and 69.3 (+/-10.3) in the lung cancer group with COPD. Lung cancer patients with COPD were heavier smokers or ex-smokers in comparison to lung cancer patients without COPD. Among lung cancer patients with COPD squamous cell carcinoma and adenocarcinoma (33.3% each) were the most frequent histological types. We quantified amounts of hexanal, heptanal, octanal, nonanal, propanoic and nonanoic acid in exhaled breath samples. We observed statistically significant lower levels of propanoic acid in lung cancer patients without COPD in comparison to those with COPD (95% CI (1.7-13.1)). There were no differences in the content of exhaled propanoic acid between gender or lung cancer histology groups. CONCLUSIONS: Propanoic acid in exhaled breath samples could be used to discriminate between lung cancer patients without and with COPD. Further studies are required to confirm this hypothesis. Supported by FIS (Formación en Investigación en Salud):
Acta Chromatographica, 2013
Summary In the present study, we have developed and validated an analytical method for the determ... more Summary In the present study, we have developed and validated an analytical method for the determination of meloxicam in liposomes using high-performance liquid chromatography-ultraviolet (HPLC-UV). Chromatographic separation was carried out on an Ascentis RP amide C16 column selecting a mobile phase composed of acetonitrile-0.3% formic acid solution (40:60, v/v) adjusted at pH 2.8. The mobile phase flow rate selected was 0.5 mL min−1 and UV detection at 355 nm. Piroxicam was chosen as internal standard. All the analyses were performed at temperatures of 40.0 ± 0.5°C. The calibration curve was linear over the range 18–420 ng mL−1. Relative standard deviation (RSD) for precision was <1.03%. Accuracy ranged between 98.53% and 101.41% with RSD lower than 1.5%. LOD and LOQ were 5 ng mL−1 and 15 ng mL−1, respectively. The method was simple, rapid, and easy to apply, making it very suitable for routine analysis of meloxicam in liposomes. The method could also be used with reliability for the determination of me...
Biochemical and Biophysical Research Communications, 1999
The three-dimensional structure of-conotoxin MVIID has been determined in aqueous solution by two... more The three-dimensional structure of-conotoxin MVIID has been determined in aqueous solution by two-dimensional 1 H NMR techniques. A total of 267 relevant upper-bound distance restraints were used to obtain a family of convergent structures using molecular dynamics methods. A standard simulated annealing protocol using the XPLOR program included in ARIA provided a total of 18 final structures. The averaged RMSD between these structures and the mean atomic coordinates was 0.8 ؎ 0.3 Å for the backbone atoms. The highest mobility was observed in the segments between residues 10 to 13, comprising Tyr 13, one of the residues shown to be important for binding of-conotoxin GVIA and MVIIA to N-type calcium channels. The three-dimensional structure is stabilised by the three disulfide bonds and includes a short antiparallel -strand between residues 5-8, 23-25 and 19-21. The folding for this non-N-type calcium channel blocker is similar to that previously calculated for-conotoxins GVIA, MVIIA and MVIIC. This suggests the disulfide bond pattern fixes the structure. The reported three-dimensional information can be used to advantage in order to highlight the structural parameters involved in discrimination among calcium channel subtypes.
Marine Drugs
Brain-derived neurotrophic factor (BDNF) regulates dendritic branching and dendritic spine morpho... more Brain-derived neurotrophic factor (BDNF) regulates dendritic branching and dendritic spine morphology, as well as synaptic plasticity and long-term potentiation. Consequently, BDNF deficiency has been associated with some neurological disorders such as Alzheimer’s, Parkinson’s or Huntington’s diseases. In contrast, elevated BDNF levels correlate with recovery after traumatic central nervous system (CNS) injuries. The utility of BDNF as a therapeutic agent is limited by its short half-life in a pathological microenvironment and its low efficacy caused by unwanted consumption of non-neuronal cells or inappropriate dosing. Here, we tested the activity of chitosan microsphere-encapsulated BDNF to prevent clearance and prolong the efficacy of this neurotrophin. Neuritic growth activity of BDNF release from chitosan microspheres was observed in the PC12 rat pheochromocytoma cell line, which is dependent on neurotrophins to differentiate via the neurotrophin receptor (NTR). We obtained a r...
Biochemistry and molecular biology international, 1996
Several spectroscopic methods have been used to study the structure of beta-lactoglobulin B at pH... more Several spectroscopic methods have been used to study the structure of beta-lactoglobulin B at pH 2.1 in the presence of 8M urea. Fluorescence and polarization of fluorescence spectroscopy measurements indicate that the two tryptophanyl residues of the protein are exposed to the solvent in the denatured state. CD in the far-UV indicates that the amount of secondary structure in the denatured state is comparable to that found in the native state, whereas the CD spectrum in the near-UV shows that the tertiary structure is not completely disordered. The results of one-dimensional 1H NMR spectroscopy show that some local non-random structure is maintained in the denatured state, but most of the polypeptide chain has an extended non-globular conformation under the conditions of the present experiments. This conclusion is reinforced by the results of two-dimensional 1H NMR conducted on denatured samples of beta-lactoglobulin B. The study of states with intermediate levels of order will ai...
Proteins: Structure, Function, and Bioinformatics, 2004
Pleckstrin1 is a major substrate for protein kinase C in platelets and leukocytes, and comprises ... more Pleckstrin1 is a major substrate for protein kinase C in platelets and leukocytes, and comprises a central DEP (disheveled, Egl-10, pleckstrin) domain, which is flanked by two PH (pleckstrin homology) domains. DEP domains display a unique alpha/beta fold and have been implicated in membrane binding utilizing different mechanisms. Using multiple sequence alignments and phylogenetic tree reconstructions, we find that 6 subfamilies of the DEP domain exist, of which pleckstrin represents a novel and distinct subfamily. To clarify structural determinants of the DEP fold and to gain further insight into the role of the DEP domain, we determined the three-dimensional structure of the pleckstrin DEP domain using heteronuclear NMR spectroscopy. Pleckstrin DEP shares main structural features with the DEP domains of disheveled and Epac, which belong to different DEP subfamilies. However, the pleckstrin DEP fold is distinct from these structures and contains an additional, short helix alpha4 inserted in the beta4-beta5 loop that exhibits increased backbone mobility as judged by NMR relaxation measurements. Based on sequence conservation, the helix alpha4 may also be present in the DEP domains of regulator of G-protein signaling (RGS) proteins, which are members of the same DEP subfamily. In pleckstrin, the DEP domain is surrounded by two PH domains. Structural analysis and charge complementarity suggest that the DEP domain may interact with the N-terminal PH domain in pleckstrin. Phosphorylation of the PH-DEP linker, which is required for pleckstrin function, could regulate such an intramolecular interaction. This suggests a role of the pleckstrin DEP domain in intramolecular domain interactions, which is distinct from the functions of other DEP domain subfamilies found so far.
Journal of Molecular Biology, 1999
In this work, we have analyzed the relative importance of secondary versus tertiary interactions ... more In this work, we have analyzed the relative importance of secondary versus tertiary interactions in stabilizing and guiding protein folding. For this purpose, we have designed four different mutants to replace the ahelix of the G B1 domain by a sequence with strong b-hairpin propensity in isolation. In particular, we have chosen the sequence of the second b-hairpin of the G B1 domain, which populates the native conformation in aqueous solution to a signi®cant extent. The resulting protein has roughly 30 % of its sequence duplicated and maintains the 3D-structure of the wild-type protein, but with lower stability (up to À5 kcal/mol). The loss of intrinsic helix stability accounts for about 80 % of the decrease in free energy, illustrating the importance of local interactions in protein stability. Interestingly enough, all the mutant proteins, included the one with the duplicated b-hairpin sequence, fold with similar rates as the G B1 domain. Essentially, it is the nature of the rate-limiting step in the folding reaction that determines whether a particular interaction will speed up, or not, the folding rates. While local contacts are important in determining protein stability, residues involved in tertiary contacts in combination with the topology of the native fold, seem to be responsible for the speci®city of protein structures. Proteins with non-native secondary structure tendencies can adopt stable folds and be as ef®cient in folding as those proteins with native-like propensities.
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Papers by Concepción Civera