Effects of oxidative stress on plasma membrane fluidity: biological consequences

El estrés oxidativo (OS) es característico de muchas enfermedades y se produce cuando hay un desequilibrio entre oxidantes y antioxidantes, lo cual favorece un estado oxidativo que genera especies reactivas de oxígeno y de nitrógeno. Los lípidos de la membrana plasmática son dianas preferentes del OS y ello tiene como consecuencia la peroxidación lipídica. Este proceso modifica propiedades de la membrana tales como su fluidez, característica física muy importante conocida por modular la localización de las proteínas de membrana y las uniones receptor-ligando. Objetivos: 1) Evaluar el efecto del OS en la regionalización de la fluidez en la membrana plasmática de células vivas tales como macrófagos THP-1 y linfocitos MEC-1, de manera individualizada. 2) Analizar, en estas células, la relación entre la peroxidación lipídica y la fluidez de membrana. 3) Estudiar el efecto del OS sobre la unión receptor-ligando y sobre la fluidez de membrana: lipopolisacárido/receptores de tipo Toll (TLR2/4) en macrófagos y progesterone-induced blocking factor (PIBF)/PIBF-receptor en linfocitos. Material y Métodos: Se estandarizó la metodología two-photon microscopy por primera vez en la Universidad Autónoma de Barcelona, para analizar la fluidez de membrana en células vivas individuales. Conjuntamente se ha desarrollado un nuevo software capaz de medir el tamaño y el número de los dominios lipídicos de membrana. El OS se indujo mediante H2O2 y se empleó la sonda fluorescente Laurdan para detectar las diferencias de fluidez en la membrana plasmática. Se utilizaron LPS y PIBF soluble en macrófagos y linfocitos respectivamente, para analizar interacciones receptor-ligando en condiciones OS. Resultados: En los macrófagos se observó un aumento significativo, dependiente de la concentración de H2O2, en la frecuencia de regiones lipídicas rígidas principalmente compuestas por dominios lipid raft, a expensas de las regiones de fluidez intermedia. Asimismo, se detectó en condiciones de OS, un mayor número, aunque no un mayor tamaño, de dominios lipid raft. La activación de macrófagos con LPS incrementó la frecuencia de regiones fluidas en las membranas, efecto que fue inhibido en condiciones de OS. En cuanto a la función de los macrófagos, se detectó una disminución en la secreción de TNFα en condiciones oxidantes. En los linfocitos se observó un aumentó significativo en la frecuencia de regiones lipídicas rígidas, a expensas de las regiones fluidas, en condiciones de OS. Por otro lado, la unión del PIBF a su receptor, provocó un aumentó en la rigidez de la membrana plasmática debido al clustering de dominios lipid raft. Por el contrario, cuando se indujo OS en linfocitos en presencia de PIBF, se inhibió el clustering de dominios lipid raft y también disminuyó el reconocimiento del receptor de PIBF a su ligando. Conclusiones: 1) Se ha evaluado en células vivas, de forma individual, la dinámica lipídica de la membrana plasmática. 2) Una consecuencia general importante es que, durante el OS, tanto en macrófagos como en linfocitos la membrana plasmática se vuelve más rígida. 3) La fluidez de membrana cambia de forma distinta en los dos tipos celulares estudiados, como consecuencia de las interacciones receptor-ligando: durante la unión LPS-TLR2/4 se observó un aumento en la fluidez de la membrana plasmática de los macrófagos y, por el contrario, durante la unión PIBF/PIBF-R la membrana de los linfocitos se rigidificó, aumentando el clustering de los dominios lipid raft. 4) No obstante, en ambos casos el OS inhibió los cambios en la fluidez de membrana inducidos por la unión receptor-ligando.Oxidative stress is present in many diseases and it is produced in cells when an imbalance between oxidants and antioxidants occurs, favoring an oxidant status which produce reactive oxygen and nitrogen species. Lipids in plasma membrane are one of the preferential targets giving rise to lipid peroxidation. This process modifies membrane properties such as membrane fluidity, a very important physical feature known to modulate membrane protein localization and receptor-ligand binding. Aims: 1) To evaluate the effect of oxidative stress on plasma membrane fluidity regionalization of single living THP-1 macrophages and MEC-1 lymphocytes. 2) To analyze, in these cells, the relationship between lipid peroxidation and membrane fluidity. 3) To study the effect of oxidative stress on receptor-ligand binding and membrane fluidity: lipopolysaccharide/toll-like receptors (TLR2/4) in macrophages and progesterone-induced blocking factor (PIBF)/PIBF-receptor in lymphocytes. Material and Methods: Two-photon microscopy was standardized for the first time in Universidad Autónoma de Barcelona by our laboratory, to analyze membrane fluidity in single living cells. It was also developed a new software application to analyze membrane lipid domain size and number. Cellular oxidative stress was induced by H2O2; the fluorescent probe Laurdan was applied to evaluate plasma membrane fluidity changes. LPS in macrophages or soluble PIBF in lymphocytes were used to analyze receptor-ligand interactions under oxidative stress. Results: Macrophages showed a significant H2O2 concentration dependent increase in the frequency of rigid lipid regions, mainly attributable to lipid rafts, at the expense of the intermediate fluidity regions. Under oxidative stress conditions, an increase in number, but not in size, of lipid raft domains was detected. Macrophage activation by LPS increase the frequency of fluid regions, which was inhibited by oxidative stress. Concerning macrophage function, secretion of TNFα under oxidative conditions was decreased. Lymphocytes showed a significant increase in the frequency of rigid lipid regions, at the expense of fluid regions, under oxidative stress conditions. Upon PIBF binding to its receptor, lymphocyte plasma membrane became more rigid due to clustering of lipid rafts. However, when PIBF bound lymphocytes were placed in oxidizing conditions, lipid raft clustering was inhibited and PIBF binding to its receptor was also decreased. Conclusions: 1) In single living cells plasma membrane lipid dynamics was evaluated. 2) An important general consequence of oxidative stress is that both in macrophages and lymphocytes plasma membrane becomes more rigid. 3) Receptor-ligand interactions have an effect on membrane fluidity, which vary greatly between the two cell types studied: macrophages and lymphocytes. Upon receptor-ligand binding, macrophage plasma membrane became more fluid while lymphocytes plasma membrane became more rigid. Our results suggest that lipid raft clustering is linked to cell function: upon PIBF binding to its receptor lipid raft clustering occurs in lymphocytes; however, upon LPS/TLR2/4 lipid raft clustering does not occur in macrophages. 4) Nevertheless, the effect induced by receptor-ligand binding on membrane fluidity was inhibited during oxidative stress in both cases

Participatory teaching methods application for the assimilation of the contents and their evaluation

En los últimos años, la educación se ha centrado en el aprendizaje y en el desarrollo de métodos docentes enfocados hacia la evaluación continua y el fomento de la motivación y participación del alumnado. Con estos fines, en este Proyecto de Innovación Docente se han aplicado técnicas de gamificación y de evaluación crítica y objetiva entre compañeros. Se utilizó la plataforma “Kahoot” como medio para la gamificación, destacando la elevada satisfacción alcanzada por los alumnos, que confirmaron que fue de gran ayuda en el proceso de aprendizaje. En cuanto a los cuestionarios realizados, se resalta la menor atención por parte de los alumnos a la exposición de los trabajos de sus compañeros en comparación con las clases prácticas y la diferencia entre las calificaciones otorgadas por ellos y las del profesor, lo cual destaca la necesidad de fomentar el espíritu crítico en el alumnado. Cabe concluir que la gamificación es un método eficaz para fomentar la participación en clase y mejorar la asimilación de contenidos, así como una herramienta útil que permite al profesor incidir en aquellos conceptos menos entendidos.Over the last years, education has been focused on the learning procedure and the development of teaching methods committed to the continuous assessment and to promote the participation and motivation of the students. For these purposes, techniques such as gamification and critical evaluation among students have been applied in this teaching innovation project. The "Kahoot" platform was used for gamification, highlighting the great satisfaction achieved by the students, who confirmed that it was a helpful tool in the learning process. As regards questionnaires carried out, it must be emphasized that students pay less attention to their classmates’ work presentation in comparison to the professor’s practical lessons, as well as the difference between the grades granted by students and the professor, which highlights the need to encourage the critical thinking among students. To conclude, gamification is an effective method to promote the participation in class and to improve the assimilation of the provided content, besides a useful tool which enables the teacher to stress those misunderstood concepts

Bevacizumab plus preoperative chemotherapy in operable HER2 negative breast cancer: biomarkers and pathologic response

Purpose: The primary aim of this trial was to assess the rate of pathologic complete responses (pCR) of doxorubicin/cyclophosphamide (AC) followed by bevacizumab/docetaxel (BT), as neoadjuvant therapy for breast cancer (BC). Furthermore, the association between biomarkers and the pCR was explored. Methods: Patients with HER-negative operable stage II–III BC ≥2 cm were enrolled. Four cycles of AC (A 60 mg/m2 and C 600 mg/m2, every 3 weeks) followed by 4 cycles of BT (B 15 mg/kg and T 75 mg/m2, every 3 weeks), were planned. A core-biopsy was performed for biological markers assessment. Results: Seventy-two women were included. Forty-three (63 %) patients were hormone receptor-positive. Sixty-four (89 %) completed the planned treatment, and 66 evaluable patients underwent surgery (92 %): a pCR was achieved in 16 of them (24, 95 % CI 15–36 %). pCR was significantly higher in tumors hormone receptor-negative, and in those with Angiotensin II type 1 receptor (AGTR1) protein overexpression. The overall clinical response rate was 86 % (95 % CI 76–93 %), including 42 complete responses. No unexpected toxicities or treatment-related deaths were observed. Conclusion: This regimen showed a remarkable clinical and pathological activity: the suggested relation between pCR and AGTR1 overexpression should be confirmed in larger trials.Financial support for this research was provided by Roche Farma, S.A

Electronic health records and patient registries in medical oncology departments in Spain

We aimed to evaluate the current situation of electronic health records (EHRs) and patient registries in the oncology departments of hospitals in Spain. This was a cross-sectional study conducted from December 2018 to September 2019. The survey was designed ad hoc by the Outcomes Evaluation and Clinical Practice Section of the Spanish Society of Medical Oncology (SEOM) and was distributed to all head of medical oncology department members of SEOM. We invited 148 heads of oncology departments, and 81 (54.7%) questionnaires were completed, with representation from all 17 Spanish autonomous communities. Seventy-seven (95%) of the respondents had EHRs implemented at their hospitals; of them, over 80% considered EHRs to have a positive impact on work organization and clinical practice, and 73% considered that EHRs improve the quality of patient care. In contrast, 27 (35.1%) of these respondents felt that EHRs worsened the physician-patient relationship and conveyed an additional workload (n = 29; 37.6%). Several drawbacks in the implementation of EHRs were identified, including the limited inclusion of information on both outpatients and inpatients, information recorded in free text data fields, and the availability of specific informed consent. Forty-six (56.7%) respondents had patient registries where they recorded information from all patients seen in the department. Our study indicates that EHRs are almost universally implemented in the hospitals surveyed and are considered to have a positive impact on work organization and clinical practice. However, EHRs currently have several drawbacks that limit their use for investigational purposes. Not applicable The online version contains supplementary material available at 10.1007/s12094-021-02614-9

A Phase I/II Clinical Trial to evaluate the efficacy of baricitinib to prevent respiratory insufficiency progression in onco-hematological patients affected with COVID19: a structured summary of a study protocol for a randomised controlled trial

Objectives: Baricitinib is supposed to have a double effect on SARS-CoV2 infection. Firstly, it reduces the inflammatory response through the inhibition of the Januse-Kinase signalling transducer and activator of transcription (JAK-STAT) pathway. Moreover, it reduces the receptor mediated viral endocytosis by AP2-associated protein kinase 1 (AAK1) inhibition. We propose the use of baricinitib to prevent the progression of the respiratory insufficiency in SARS-CoV2 pneumonia in onco-haematological patients. In this phase Ib/II study, the primary objective in the safety cohort is to describe the incidence of severe adverse events associated with baricitinib administration. The primary objective of the randomized phase (baricitinib cohort versus standard of care cohort) is to evaluate the number of patients who did not require mechanical oxygen support since start of therapy until day +14 or discharge (whichever it comes first). The secondary objectives of the study (only randomized phase of the study) are represented by the comparison between the two arms of the study in terms of mortality and toxicity at day+30. Moreover, a description of the immunological related changes between the two arms of the study will be reported. Trial design: The trial is a phase I/II study with a safety run-in cohort (phase 1) followed by an open label phase II randomized controlled trial with an experimental arm compared to a standard of care arm

Predicting serious complications in patients with cancer and pulmonary embolism using decision tree modelling: the EPIPHANY Index

Background: Our objective was to develop a prognostic stratification tool that enables patients with cancer and pulmonary embolism (PE), whether incidental or symptomatic, to be classified according to the risk of serious complications within 15 days. Methods: The sample comprised cases from a national registry of pulmonary thromboembolism in patients with cancer (1075 patients from 14 Spanish centres). Diagnosis was incidental in 53.5% of the events in this registry. The Exhaustive CHAID analysis was applied with 10-fold crossvalidation to predict development of serious complications following PE diagnosis. Results: About 208 patients (19.3%, 95% confidence interval (CI), 17.1-21.8%) developed a serious complication after PE diagnosis. The 15-day mortality rate was 10.1%, (95% CI, 8.4-12.1%). The decision tree detected six explanatory covariates: Hestia-like clinical decision rule (any risk criterion present vs none), Eastern Cooperative Group performance scale (ECOG-PS; = 2), O-2 saturation (= 90%), presence of PE-specific symptoms, tumour response (progression, unknown, or not evaluated vs others), and primary tumour resection. Three risk classes were created (low, intermediate, and high risk). The risk of serious complications within 15 days increases according to the group: 1.6, 9.4, 30.6%; P<0.0001. Fifteen-day mortality rates also rise progressively in low-, intermediate-, and high-risk patients: 0.3, 6.1, and 17.1%; P<0.0001. The cross-validated risk estimate is 0.191 (s.e. = 0.012). The optimism-corrected area under the receiver operating characteristic curve is 0.779 (95% CI, 0.717-0.840). Conclusions: We have developed and internally validated a prognostic index to predict serious complications with the potential to impact decision-making in patients with cancer and PE

Safety and efficacy of ribociclib plus letrozole in patients with HR+, HER2– advanced breast cancer: Results from the Spanish sub-population of the phase 3b CompLEEment-1 trial

Background: Breast cancer is the most common malignancy and the second leading cause of cancer-related mortality in Spanish women. Ribociclib in combination with endocrine therapy (ET) has shown superiority in prolonging survival in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) vs. ET alone.Methods: CompLEEment-1 is a single-arm, open-label phase 3b trial evaluating ribociclib plus letrozole in a broad population of patients with HR+, HER2- ABC. The primary endpoints were safety and tolerability. Here we report data for Spanish patients enrolled in CompLEEment-1.Results: A total of 526 patients were evaluated (median follow-up: 26.97 months). Baseline characteristics showed a diverse population with a median age of 54 years. At study entry, 56.5% of patients had visceral metastases and 8.7% had received prior chemotherapy for advanced disease. Rates of all-grade and Grade >= 3 adverse events (AEs) were 99.0% and 76.2%, respectively; 21.3% of patients experienced a serious AE, and 15.8% of AEs led to treatment discontinuation. AEs of special interest of neutropenia, increased alanine aminotransferase, increased aspartate aminotransferase and QTcF prolongation occurred in 77.8%, 14.8%, 11.4% and 4.0% of patients, respectively. Patients aged >70 years experienced increased rates of all-grade and Grade >= 3 neutropenia and anemia. Efficacy results were consistent with the global study.Conclusions: Results from Spanish patients enrolled in CompLEEment-1 are consistent with global data showing efficacy and a manageable safety profile for ribociclib plus letrozole treatment in patients with HR+, HER2-ABC, including populations of interest (NCT02941926).Trial registration: ClinicalTrials.gov NCT0294192

Health-related quality of life with palbociclib plus endocrine therapy versus capecitabine in postmenopausal patients with hormone receptor–positive metastatic breast cancer: Patient-reported outcomes in the PEARL study

Background: The PEARL study showed that palbociclib plus endocrine therapy (palbociclib/ET) was not superior to capecitabine in improving progression-free survival in postmenopausal patients with metastatic breast cancer resistant to aromatase inhibitors, but was better tolerated. This analysis compared patient-reported outcomes. Patients and methods: The PEARL quality of life (QoL) population comprised 537 patients, 268 randomised to palbociclib/ET (exemestane or fulvestrant) and 269 to capecitabine. Patients completed the European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23 and EQ-5D-3L questionnaires. Changes from the baseline and time to deterioration (TTD) were analysed using linear mixed-effect and stratified Cox regression models, respectively. Results: Questionnaire completion rate was high and similar between treatment arms. Significant differences were observed in the mean change in global health status (GHS)/QoL scores from the baseline to cycle 3 (2.9 for palbociclib/ET vs. -2.1 for capecitabine (95% confidence interval [CI], 1.4–8.6; P = 0.007). The median TTD in GHS/QoL was 8.3 months for palbociclib/ET versus 5.3 months for capecitabine (adjusted hazard ratio, 0.70; 95% CI, 0.55–0.89; P = 0.003). Similar improvements for palbociclib/ET were also seen for other scales as physical, role, cognitive, social functioning, fatigue, nausea/vomiting and appetite loss. No differences were observed between the treatment arms in change from the baseline in any item of the EQ-5D-L3 questionnaire as per the overall index score and visual analogue scale. Conclusion: Patients receiving palbociclib/ET experienced a significant delay in deterioration of GHS/QoL and several functional and symptom scales compared with capecitabine, providing additional evidence that palbociclib/ET is better tolerated. Trial registration number: NCT02028507 (ClinTrials.gov). EudraCT study number: 2013-003170-27. © 2021 The Author(s

Palbociclib in combination with endocrine therapy versus capecitabine in hormonal receptor-positive, human epidermal growth factor 2-negative, aromatase inhibitor-resistant metastatic breast cancer: a phase III randomised controlled trial—PEARL

Background: Palbociclib plus endocrine therapy (ET) is the standard treatment of hormone receptor-positive and human epidermal growth factor receptor 2-negative, metastatic breast cancer (MBC). However, its efficacy has not been compared with that of chemotherapy in a phase III trial. Patients and methods: PEARL is a multicentre, phase III randomised study in which patients with aromatase inhibitor (AI)-resistant MBC were included in two consecutive cohorts. In cohort 1, patients were randomised 1 : 1 to palbociclib plus exemestane or capecitabine. On discovering new evidence about estrogen receptor-1 (ESR1) mutations inducing resistance to AIs, the trial was amended to include cohort 2, in which patients were randomised 1 : 1 between palbociclib plus fulvestrant and capecitabine. The stratification criteria were disease site, prior sensitivity to ET, prior chemotherapy for MBC, and country of origin. Co-primary endpoints were progression-free survival (PFS) in cohort 2 and in wild-type ESR1 patients (cohort 1 + cohort 2). ESR1 hotspot mutations were analysed in baseline circulating tumour DNA. Results: From March 2014 to July 2018, 296 and 305 patients were included in cohort 1 and cohort 2, respectively. Palbociclib plus ET was not superior to capecitabine in both cohort 2 [median PFS: 7.5 versus 10.0 months; adjusted hazard ratio (aHR): 1.13; 95% confidence interval (CI): 0.85-1.50] and wild-type ESR1 patients (median PFS: 8.0 versus 10.6 months; aHR: 1.11; 95% CI: 0.87-1.41). The most frequent grade 3-4 toxicities with palbociclib plus exemestane, palbociclib plus fulvestrant and capecitabine, respectively, were neutropenia (57.4%, 55.7% and 5.5%), hand/foot syndrome (0%, 0% and 23.5%), and diarrhoea (1.3%, 1.3% and 7.6%). Palbociclib plus ET offered better quality of life (aHR for time to deterioration of global health status: 0.67; 95% CI: 0.53-0.85). Conclusions: There was no statistical superiority of palbociclib plus ET over capecitabine with respect to PFS in MBC patients resistant to AIs. Palbociclib plus ET showed a better safety profile and improved quality of life

Rhamnolipids: diversity of structures, microbial origins and roles

Rhamnolipids are glycolipidic biosurfactants produced by various bacterial species. They were initially found as exoproducts of the opportunistic pathogen Pseudomonas aeruginosa and described as a mixture of four congeners: α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoate (Rha-Rha-C10-C10), α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxydecanoate (Rha-Rha-C10), as well as their mono-rhamnolipid congeners Rha-C10-C10 and Rha-C10. The development of more sensitive analytical techniques has lead to the further discovery of a wide diversity of rhamnolipid congeners and homologues (about 60) that are produced at different concentrations by various Pseudomonas species and by bacteria belonging to other families, classes, or even phyla. For example, various Burkholderia species have been shown to produce rhamnolipids that have longer alkyl chains than those produced by P. aeruginosa. In P. aeruginosa, three genes, carried on two distinct operons, code for the enzymes responsible for the final steps of rhamnolipid synthesis: one operon carries the rhlAB genes and the other rhlC. Genes highly similar to rhlA, rhlB, and rhlC have also been found in various Burkholderia species but grouped within one putative operon, and they have been shown to be required for rhamnolipid production as well. The exact physiological function of these secondary metabolites is still unclear. Most identified activities are derived from the surface activity, wetting ability, detergency, and other amphipathic-related properties of these molecules. Indeed, rhamnolipids promote the uptake and biodegradation of poorly soluble substrates, act as immune modulators and virulence factors, have antimicrobial activities, and are involved in surface motility and in bacterial biofilm development