Search

The aim of the present study was to assess the presence of perfluoroalkyl acids (PFAAs), namely perfluoroalkane sulfonates and perfluoroalkyl carboxylic acids, in Spanish river basins in order to: identify potential spatiotemporal variations; evaluate the effectiveness of the measures implemented for the reduction/elimination of these pollutants; verify the fulfillment of the Environmental Quality Standards (EQSs) in the European Union. PFOS and PFOA were determined in 116 water samples from four sites in the Duero basin, the largest in the Iberian Peninsula, collected seasonally from 2013 to 2020. In addition, 30 fish sample composites from the sample banks of Duero, Tagus, Ebro, Eastern Cantabrian and Catalonian basins were analyzed for 15 PFAAs. Median PFOS and PFOA concentrations were 0.72 and 0.42 ng/L, ranging from values below the limit of quantification (LOQ) to 81 and 22 ng/L, respectively. During the studied period, 51% of water samples were above the EQS of 0.65 ng/L for PFOS. In the case of fish, the PFOS range was

[EN] BACKGROUND: Quinolones are the second most frequent cause of hypersensitivity reactions (HSRs) to antibiotics. A marked increase in the number of patients with HSRs to quinolones has been detected. OBJECTIVE: To describe the clinical characteristics of patients with HSRs to quinolones and present methods for their diagnosis. METHODS: Patients attending the allergy unit due to reactions suggestive of HSRs to quinolones were prospectively evaluated between 2005 and 2018. Diagnosis was achieved using clinical history, skin tests (STs), basophil activation tests (BATs), and drug provocation tests (DPTs) if ST and BAT results were negative. RESULTS: We included 128 subjects confirmed as having HSRs to quinolones and 42 found to be tolerant. Anaphylaxis was the most frequent entity in immediate HSRs and was most commonly induced by moxifloxacin. Patients were evaluated a median of 150 days (interquartile range, 60-365 days) after the reaction. Of patients who underwent ST and BAT, 40.7% and 70%, respectively, were positive. DPT with a quinolone was performed in 48 cases, giving results depending on the culprit drug: when moxifloxacin was involved, 62.5% of patients gave a positive DPT result to ciprofloxacin, whereas none reacted to levofloxacin. The risk of HSR was 96 times higher in subjects who reported moxifloxacin-induced anaphylaxis and 18 times higher in those reporting immediate reactions compared with clinical entities induced by quinolones other than moxi-floxacin and nonimmediate reactions. CONCLUSIONS: The diagnosis of HSR to quinolones is complex. The use of clinical history is essential as a first step. BAT shows higher sensitivity than STs. DPTs can be useful for finding safe alternative quinolones.

[EN] Transient absorption spectroscopy in combination with in silico methods has been employed to study the interactions between human serum albumin (HSA) and the anti-psychotic agent chlorpromazine (CPZ) as well as its two demethylated metabolites (MCPZ and DCPZ). Thus, solutions containing CPZ, MCPZ or DCPZ and HSA (molar ligand:protein ratios between 1:0 and 1:3) were submitted to laser flash photolysis and the Delta A(max) value at lambda = 470 nm, corresponding to the triplet excited state, was monitored. In all cases, the protein-bound ligand exhibited higher Delta Amax values measured after the laser pulse and were also considerably longer-lived than the non-complexed forms. This is in agreement with an enhanced hydrophilicity of the metabolites, due to the replacement of methyl groups with H that led to a lower extent of protein binding. For the three compounds, laser flash photolysis displacement experiments using warfarin or ibuprofen indicated Sudlow site I as the main binding site. Docking and molecular dynamics simulation studies revealed that the binding mode of the two demethylated ligands with HSA would be remarkable different from CPZ, specially for DCPZ, which appears to come from the different ability of their terminal ammonium groups to stablish hydrogen bonding interactions with the negatively charged residues within the protein pocket (Glu153, Glu292) as well as to allocate the methyl groups in an apolar environment. DCPZ would be rotated 180 degrees in relation to CPZ locating the aromatic ring away from the Sudlow site I of HSA. (C) 2019 Elsevier B.V. All rights reserved.

[EN] Phototoxic effects of 6,8 dihalogenated quinolones confers to this type of molecules a potential property as photochemotherapeutic agents. Two photodehalogenation processes seem to be involved in the remarkable photoinduced cellular damage. In this context, a new 6,8 dihalogenated quinolone 1 (1-methyl-6,8-difluoro-4-oxo-7-aminodimethy1-1,4-dihydroquinoline-3-carboxylic acid) was synthesized looking for improving the phototoxic properties of fluoroquinolones (FQ) and to determine the role of the photodegradation pathways in the FQ phototoxicity. With this purpose, fluorescence emissions, laser flash photolysis experiments and photodegradation studies were performed with compound 1 using 1-ethyl-6,8-difluoro-4-oxo-7-aminodimethy1-1,4-dihidroquinoline-3-carboxylic acid (2) and lomefloxacin (LFX) as reference compounds. The shortening of alkyl chain of the N(1) of the quinolone ring revealed a lifetime increase of the reactive aryl cation generated from photolysis of the three FQ and a significant reduction of the FQ photodegradation quantum yield. The fact that these differences were smaller when the same study was done using a hydrogen donor solvent (ethanol-aqueous buffer, 50/50 v/v) evidenced the highest ability of the reactive intermediate arising from 1 to produce intermolecular alkylations. These results were correlated with in vitro 3T3 NRU phototoxicity test. Thus, when PhotoIrritation-Factor (PIF) was determined for 1, 2 and LFX using cytotoxicity profiles of BALB/c 3T3 fibroblasts treated with each compound in the presence and absence of UVA light, a PIF more higher than 30 was obtained for 1 while the values for 2 and LFX were only higher than 8 and 10, respectively. Thereby, the present study illustrates an approach to modulate the photosensitizing properties of FQ with the purpose to improve the chemotherapeutic properties of antitumor quinolones. Moreover, the results obtained in this study also evidence that the key pathway responsible for the phot

Water pollution by wastewater containing dyes is an environmental issue that can be mitigated by the use of advanced oxidation processes (AOP). Pulsed light (PL) is an emerging food processing technology that uses eco-friendly lamps and can potentially be adapted as light source of an UV-based AOP. In the present work, a PL/H 2 O 2 process was tested for the decolourization of two azo dyes, and a pulsed light/H 2 O 2 /ferrioxalate process was tested for the decolourization of one azo dye. The efficiency of the PL/H 2 O 2 process in a batch reactor under different parametric values: dye concentration, pH, H 2 O 2 and salt doses was followed by spectrophotometry and fitted to first-order kinetics; and several degradation products were detected. In the PL/H 2 O 2 process, decolourization rates increased at low dye concentrations and high H 2 O 2 doses, were pH-dependent and were inhibited by the addition of NaCl, Na 2 SO 3 or Na 2 CO 3. More than 50% decolouration was achieved with the PL/H 2 O 2 process for both dyes after applying 54 J/cm 2 (25 light pulses). The PL/H 2 O 2 /ferrioxalate process achieved >95% decolouration for Methyl orange when applying 21 J/cm 2 (10 pulses); that level of energy can be supplied by PL commercial systems in nine and four seconds respectively. No known toxic degradation products were detected. Results show that a PL/H 2 O 2 process has potential to be used for the efficient degradation of dyes from wastewater. Furthermore, the efficacy of this process can be improved by the use of ferrioxalate. PL technology could become an alternative light source to contribute to decrease the environmental impact of wastewater produced by the dyeing industry. © 2019

[EN] Diclofenac (DCF) can cause adverse reactions such as gastrointestinal, renal and cardiovascular disorders; therefore, topical administration may be an attractive alternative to the management of local pain in order to avoid these side effects. However, previous studies have shown that DCF, in combination with sunlight, displays capability to induce photosensitivity disorders. In humans, DCF is biotransformed into hydroxylated metabolites at positions 4¿ and 5 (4¿OH-DCF and 5OH-DCF), and this chemical change produces non negligible alterations of the drug chromophore, resulting in a significant modification of its light-absorbing properties. In the present work, 5OH-DCF exhibited higher photo(geno)toxic potential than the parent drug, as shown by several in vitro assays (3T3 NRU phototoxicity, DNA ssb gel electrophoresis and COMET), whereas 4¿OH-DCF did not display significant photo(geno)toxicity. This could be associated, at least partially with their more efficient UV-light absorption by 5OH-DCF metabolite and with a higher photoreactivity. Interestingly, most of the cellular DNA damage photosensitized by DCF and 5OH-DCF was repaired by the cells after several hours, although this effect was not complete in the case of 5OH-DCF.

The Stockholm Convention (SC) on Persistent Organic Pollutants (POPs) calls for the Parties’ effectiveness evaluation of those measures taken to meet the reduction and eventual elimination of POPs from the environment. With that goal, air concentrations of different POP families have been measured uninterruptedly since 2008 under the Spanish Monitoring Program (SMP) by means of passive air sampling. This work focuses on data for polybrominated diphenyl ethers (PBDEs) determined in a total of 321 samples collected seasonally each year in 5 urban and 7 background sites. Neither significant temporal trends nor significant seasonal variations for total PBDE air burdens were detected. In contrast, significant variations were found among PBDE congeners. Those related to the octa-PBDE formulation significantly decreased in the study period. However, PBDEs related to the penta-formulation showed steady concentrations while PBDE-209, the congener found at the greatest levels, showed increasing or steady levels in most sampling sites. Seasonal variations were also markedly different among congeners. Concentrations of the lightest PBDEs (tri- to penta-substituted) were highly influenced by ambient temperature (T), showing maximum values in summer probably due to higher volatilization rates compared to those of heavier PBDEs. Contrarily, no clear seasonal trends were found for hexa- to deca-PBDEs, which were negatively related to precipitation; thereby, indicating an efficient atmospheric wash out by wet deposition episodes. Regarding spatial patterns, overall significant greater PBDE levels were found in cities compared to background areas, pointing out the role of highly populated areas as sources for these pollutants in Spain. Yet and especially in the case of PBDE-209, our results suggested the presence of significant unknown sources of PBDEs in some background sites. Further monitoring efforts are needed to assess potential unknown sources in the sampling network as well a

Time series (2008–2015) of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in ambient air from the Spanish Monitoring Program were analyzed. A total of 321 samples were collected seasonally each year in 5 urban and 7 background sites by means of passive air sampling. Air concentrations were higher at urban than background sites (urban vs. background concentration ranges): PCDD/Fs (26.9–1010 vs. 20.0–357 fg/m), non-ortho PCBs (0.113–3.14 vs. 0.042–2.00 pg/m) and mono-ortho PCBs (0.644–41.3 vs. 0.500–32.8 pg/m). Results showed significant decreases from 2009 for non-ortho PCBs and PCDD/Fs as well as for WHO-TEQs. These declines were sharper, and sometimes only significant, in urban places resulting in converging levels at urban and background sites for these pollutants at the end of the study period. In contrast, mono-ortho PCBs did not show any significant variation but a steady flat temporal behavior in their concentrations, suggesting the existence of different sources between mono-ortho and non-ortho PCBs. Seasonality was observed for air burdens of all these POPs. PCDD/Fs were mostly measured at higher concentrations in colder than in hot seasons, and the opposite was true for dl-PCBs. Seasonal variations for PCDD/Fs appeared to be related to changes in their sources (e.g. domestic heating, open burning) rather than to temperature per se. In contrast, environmental temperature dependent factors (e.g. increased partitioning into the gas phase) drove seasonal variations in dl-PCBs instead of seasonal changes in their sources. Regarding spatial patterns, significant greater levels of PCDD/Fs and dl-PCBs were generally found in cities compared to background areas, pointing out the role of densely populated areas as sources for these pollutants in Spain. As proven by our results, long-term monitoring activities are essential to assess and understand temporal behaviors for these POPs, as well as to evalu

Chlorpromazine (CPZ) is an anti-psychotic drug widely used to treat disorders such as schizophrenia or manic-depression. Unfortunately, CPZ exhibits undesirable side effects such as phototoxic and photoallergic reactions in humans. In general, the influence of drug metabolism on this type of reactions has not been previously considered in photosafety testing. Thus, the present work aims to investigate the possible photo(geno)toxic potential of drug metabolites, using CPZ as an established reference compound. In this case, the metabolites selected for the study are demethylchlorpromazine (DMCPZ), didemethylchlorpromazine (DDMCPZ) and chlorpromazine sulfoxide (CPZSO). The demethylated CPZ metabolites DMCPZ and DDMCPZ maintain identical chromophore to the parent drug. In this work, it has been found that the nature of the aminoalkyl side chain modulates the hydrophobicity and the photochemical properties (for instance, the excited state lifetimes), but it does not change the photoreactivity pattern, which is characterized by reductive photodehalogenation, triggered by homolytic carbon-chlorine bond cleavage with formation of highly reactive aryl radical intermediates. Accordingly, these metabolites are phototoxic to cells, as revealed by the 3T3 NRU assay; their photo-irritation factors are even higher than that of CPZ. The same trend is observed in photogenotoxicity studies, both with isolated and with cellular DNA, where DMCPZ and DDMCPZ are more active than CPZ itself. In summary, side-chain demethylation of CPZ, as a consequence of Phase I biotransformation, does not result a photodetoxification. Instead, it leads to metabolites that exhibit in an even enhanced photo(geno)toxicity.

Subjects developing anaphylaxis or urticaria/angioedema after chemically unrelated nonsteroidal antiinflammatory drug intake should not be classified as cross-hypersensitive unless they do not tolerate acetyl salicylic acid. Such cases should avoid the culprit drugs; however, they may still benefit from other nonsteroidal anti-inflammatory drugs, including acetyl salicylic acid.

Within the framework of the Spanish monitoring program, this study reports on air concentration of DDTs, HCB, HCHs, NDL-PCBs, DL-PCBs, PCDD/Fs and PBDEs measured during the five-year sampling period 2008–2013. Spanish coastal remote and urban locations were studied using PUF disk passive air samplers which were deployed and collected every three months. Despite the wide range of concentrations measured for most contaminants, a common pattern of relative abundance (median values): NDL-PCBs (36.6 pg/m) > HCB (24.8 pg/m) ≈ HCHs (17.9 pg/m) ≈ DDTs (16.6 pg/m) > PBDEs (3.65 pg/m) > DL-PCBs (2.99 pg/m) >> PCDD/Fs (0.060 pg/m) was found fairly consistent across most seasons and locations. Nevertheless, important variations in yearly concentrations were measured for different POPs. In general, higher levels of DDTs, HCHs, NDL-PCBs, DL-PCBs and PCDD/Fs were found in urban sites highlighting important differences between remote and urban sampling locations for most target contaminants. Greater concentrations of the banned organochlorine pesticides in urban locations suggested the existence of unexpected pointed sources that need to be further investigated and characterized. The limited dataset collected thus far rendered no clear temporal trends for most study target compounds, which emphasizes the necessity of the Spanish monitoring program future maintenance in time.

Metamizole is a pain-killer drug that has been banned in some countries because of its toxicity, but it is still used in many countries due to its effective analgesic and antispasmodic properties. Although large variability in the biodisposition and adverse effects of metamizole are known, factors underlying this variability are poorly understood. We analyzed the urinary recovery of metabolites, as well as the association of these profiles with genetic and non-genetic factors, in a group of 362 healthy individuals. Gender and functional polymorphisms are strongly related to metabolic profiles. N-demethylation of the active metabolite MAA is diminished in carriers of the CYP2C19*2 allele and in NAT2-slow acetylators. Acetylation of the secondary metabolite AA is decreased in men, in drinkers and in NAT2-slow acetylators with a differential effect of NAT2*5 and NAT2*6 alleles. The formylation of MAA is diminished in older subjects and in carriers of defect CYP2C9 and CYP2C19 alleles. Two novel arachidonoyl metabolites were identified for the first time in humans. Women and NAT2-slow acetylators show higher concentrations, whereas the presence of the rapid CYP2C19*17 allele is associated with lower concentrations of these metabolites. All genetic associations show a gene-dose effect. We identified for the first time genetic and non-genetic factors related to the oxidative metabolism of analgesic drug metamizole, as well as new active metabolites in humans. The phenotypic and genetic factors identified in this study have a potential application as biomarkers of metamizole biotransformation and toxicity.

The photophysical and photochemical behavior of (R)-cinacalcet (CIN) and (S)-naproxen (NPX) entrapped within liposomes has been studied. For this purpose, liposome encapsulated drugs have been prepared through thin layer evaporation and characterized by transmission electron microscopy, cryoscopy scanning electron microscopy and dynamic light scattering. Steady state and time-resolved fluorescence experiments showed similar spectra, emission quantum yields, singlet energies and lifetimes for the selected drugs, outside and inside liposomes. By contrast, laser flash photolysis experiments revealed an important enhancement of the triplet lifetimes for entrapped drugs inside liposomes, indicating the spatial confinement existing in the microenvironment prevailing in these biomimetic entities. Thus, this photophysical property shows potential as a non-invasive, direct and valuable tool to monitor encapsulation of photoactive drugs and to probe the intraliposome environment. In addition, it provides a new quantitative indicator of the capability of liposomes to act as drug carriers.

The HoxdDel(11-13) mutant is one of the animal models for human synpolydactyly, characterized by short and syndactylous digits. Here we have characterized in detail the cartilage and bone defects in these mutants. We report two distinct phenotypes: (i) a delay and change in pattern of chondrocyte maturation of metacarpals/metatarsals and (ii) formation of a poor and not centrally positioned primary ossification center in the proximal-intermediate phalanx. In the metacarpals of HoxdDel(11-13) mutants, ossification occurs postnataly, in the absence of significant Ihh expression and without the establishment of growth plates, following patterns similar to those of short bones. The strong downregulation in Ihh expression is associated with a corresponding increase of the repressor form of Gli3. To evaluate the contribution of this alteration to the phenotype, we generated double HoxdDel(11-13);Gli3 homozygous mutants. Intriguingly, these double mutants showed a complete rescue of the phenotype in metatarsals but only partial phenotypic rescue in metacarpals. Our results support Hox genes being required in a dose-dependent manner for long bone cartilage maturation and suggest that and excess of Gli3R mediates a significant part of the HoxdDel(11-13) chondrogenic phenotype.

The limb forms from a bud of mesoderm encased in a hull of ectoderm that grows out from the flank of the embryo. Coordinated signaling between the limb mesoderm and ectoderm is critical for normal limb outgrowth and patterning. The apical ectodermal ridge (AER), found at the distal tip, is a rich source of signaling molecules and has been proposed to specify distal structures and maintain the survival of cells in the underlying distal mesoderm. The dorsal and ventral non-AER ectoderm is also a source of signaling molecules and is important for dorsal-ventral patterning of the limb bud. Here we determine if this ectoderm provides cell survival signals by surgically removing the dorsal or ventral ectoderm during early chicken limb bud development and assaying for programmed cell death. We find that, similar to the AER, removal of the dorsal or ventral non-AER ectoderm results in massive cell death in the underlying mesoderm. In addition, although a re-epithelialization occurs, we find perturbations in the timing of Shh expression and, for the case of the dorsal ectoderm removal, defects in soft tissue and skeletal development along the proximal-distal axis. Furthermore, ectoderm substitution experiments show that the survival signal produced by the dorsal limb ectoderm is specific. Thus, our results argue that the non-AER ectoderm, like the AER, provides a specific survival signal to the underlying mesoderm that is necessary for normal limb development and conclusions drawn from experiments in which the non-AER ectoderm is removed, need to take into consideration this observation. © 2013 Elsevier Inc.

The formation and maintenance of the apical ectodermal ridge (AER) is critical for the outgrowth and patterning of the vertebrate limb. In the present work, we have investigated the role of Epiprofin (Epfn/Sp6), a member of the SP/KLF transcription factor family that is expressed in the limb ectoderm and the AER, during limb development. Epfn mutant mice have a defective autopod that shows mesoaxial syndactyly in the forelimb and synostosis (bony fusion) in the hindlimb and partial bidorsal digital tips. Epfn mutants also show a defect in the maturation of the AER that appears flat and broad, with a double ridge phenotype. By genetic analysis, we also show that Epfn is controlled by WNT/b-CATENIN signaling in the limb ectoderm. Since the less severe phenotypes of the conditional removal of b-catenin in the limb ectoderm strongly resemble the limb phenotype of Epfn mutants, we propose that EPFN very likely functions as a modulator of WNT signaling in the limb ectoderm.

Several members of the FGF gene family have been shown to intervene from various tissue sources to direct otic placode induction and otic vesicle formation. In this study we define the roles of FGF8, found in different expression domains during this process, in mice and chickens. By conditional inactivation of Fgf8 in distinct tissue compartments we demonstrate that Fgf8 is required in the mesoderm and endoderm during early inner ear development. In the chicken embryo, overexpression of Fgf8 from various tissue sources during otic specification leads to a loss of otic tissue. In contrast ectopic overexpression of Fgf10, a major player during murine otic induction, does not influence otic vesicle formation in chicken embryos but results in the formation of ectopic structures with a non-otic character. This study underlines the crucial role of a defined Fgf8 expression pattern controlling inner ear formation in vertebrates. © 2009 Elsevier Ireland Ltd. All rights reserved.

A crucial issue in limb development is how a correct set of precisely shaped digits forms in the digital plate. This process relies on patterning across the anterior-posterior axis of the limb bud, which is under the control of Sonic hedgehog emanating from the zone of polarizing activity. Recently, Sonic hedgehog function in the limb bud has been shown to have a dual character controlling both growth and patterning of the digital field. This finding has prompted the proposal of new models of how these two functions are achieved, and this will be discussed in this review. © 2008 Elsevier Ltd. All rights reserved.

During limb development, Sonic hedgehog (SHH) and HOX proteins are considered among the most important factors regulating digit number and identity. SHH signaling prevents the processing of GLI3 into a short form that functions as a strong transcriptional repressor. Gli3 mutant limbs are characterized by a severe polydactyly and associated ectopic anterior expression of 5′Hoxd genes. To genetically determine the involvement of 5′Hoxd genes in the polydactyly of Gli3 mutants, we have generated a compound mutant that simultaneously removes the three most 5′-located Hoxd genes and Gli3. Remarkably, the limbs that form in the absence of all four of these genes show the most severe polydactyly so far reported in the mouse. The analysis of gene expression performed in compound mutants allows us to propose that the increase in the number of digits is mediated by the gain in function of Hoxd10 and Hoxd9. Our results also support the notion that an adequate balance between positive and negative effects of different Hoxd genes is required for pentadactyly. © 2007 Elsevier Inc. All rights reserved.

Objetivo. Conocer la opinión de los formadores (tutores y colaboradores docentes) de los residentes de tercer año de medicina familiar y comunitaria (MFyC) sobre su propia actividad como docentes en aspectos relacionados con la formación, las habilidades y las cualidades necesarias para la docencia y las relaciones interprofesionales actuales y necesarias en un equipo de atención primaria con actividad docente. Diseño. Estudio cualitativo desarrollado entre junio de 2000 y mayo de 2002. Realización de un diseño muestral con población voluntaria. Emplazamiento. Unidad docente de MFyC de la Gerencia de Atención Primaria de Murcia. Participantes y/o contextos. Tutores y colaboradores docentes del programa de la residencia de MFyC. Método. Entrevista semiestructurada para la recogida de información. Análisis de contenido para la construcción de resultados a partir del análisis semiológico del discurso textual. Devolución sistemática de los resultados. Resultados. La pertenencia al equipo docente es la mayor motivación para participar en la docencia. Esta última aporta más ventajas para los tutores (afectivas, descarga asistencial) que dificultades (adaptación organizativa). El perfil del tutor se sustenta en las cualidades cientificotécnicas y personales, y el de las enfermeras, en las comunitarias. La colaboración entre enfermera y tutor es informal y las estrategias docentes más empleadas por el tutor son la orientación, la guía y el fomento de la autonomía del residente. La enfermera colabora con la docencia transmitiendo un modelo de desarrollo profesional y facilitando el trabajo en equipo. Conclusiones. Resalta la complejidad existente en el proceso formativo. La formación de posgrado de MFyC es transprofesional y no se circunscribe exclusivamente a la relación docente entre tutores y residentes. El paradigma cualitativo se manifiesta útil para obtener una visión del proceso docente desde la perspectiva de diferentes actores., Objective. To find the view of trainers (tutors and teaching assistants) of third-year family and community medicine (FCM) residents concerning their own teaching activity in areas such as training, the skills and qualities required to be a teacher and the inter-professional relationships that are current and that are needed in a primary care teaching team. Design. Qualitative study developed between June 2000 and May 2002. Sample design with a volunteer population. Setting. FCM teaching unit under the Primary Care Administration of Murcia. Participants and/or contexts. Tutors and teaching assistants in the FCM residents' programme. Method. Semi-structured interview for information gathering. Contents analysis to construct results on the basis of the semiological analysis of the textual discourse. Systematic return of the results. Results. Belonging to the teaching team is the highest motivation for taking part in teaching. It gives the tutors more benefits (affective, care load) than difficulties (organisational adaptation). The tutor profile is sustained by his/her scientific-technical and personal qualities; that of the nurse, by his/her community qualities. Collaboration between nurse and tutor is informal and the teaching strategies most employed by tutors are guidance, guide-lines and encouragement of residents' autonomy. Nurses collaborate with teaching by transmitting a model of professional development and facilitating teamwork. Conclusions. The complexity of the training process stands out. Postgraduate FCM training is cross-professional, not exclusively circumscribed by the tutor-resident teaching relationship. The qualitative paradigm is shown to be useful for obtaining a vision of the teaching process from the perspective of different actors.