Evaluación de estrategias terapéuticas basadas en sustancias antiinflamatorias y antioxidantes en retinosis pigmentaria

La retinosis pigmentaria comprende un grupo de distrofias hereditarias de retina, caracterizadas por la pérdida progresiva e irreversible de la visión, debida a la muerte de las células fotorreceptoras. Se trata de una enfermedad rara, que constituye la principal causa genética de ceguera, con una prevalencia de un afectado por cada 4000 habitantes. Mientras que la degeneración retiniana empieza con la muerte de los bastones debida a mutaciones genéticas, la muerte de los conos parece ser consecuencia de un progresivo daño oxidativo, inflamación y desequilibrio metabólico, influenciado por la liberación de sustancias tóxicas por parte de los bastones y otras células del entorno. La muerte de los bastones da lugar a la aparición de los primeros síntomas de la enfermedad, como la ceguera nocturna y la visión en túnel, y la muerte de los conos termina produciendo la perdida de la visión central. Los fotorreceptores son especialmente susceptibles al daño oxidativo y a la peroxidación lipídica debido a su elevada tasa metabólica y a los riesgos ambientales a los que están expuestos. Distintas evidencias en modelos experimentales y pacientes con retinosis pigmentaria muestran alteraciones en el estado antioxidante-oxidante y presencia de estrés oxidativo que pueden correlacionarse con una peor función visual. Según esta hipótesis oxidativa, la muerte de los bastones, principales consumidores de oxígeno de la retina durante las primeras etapas de la enfermedad, provocaría un aumento de la concentración de oxígeno o hiperoxia, que produciría estrés oxidativo, exacerbando la muerte de los bastones y contribuyendo a la muerte de los conos. En los últimos años también se ha observado una gran implicación de la inflamación en la progresión de la enfermedad, que conlleva activación de la microglía y conduce a la liberación de citoquinas proinflamatorias, como el factor de necrosis tumoral (TNFα), entre otras moléculas de señalización. El mantenimiento prolongado de elevados niveles de estas moléculas, especialmente de las citoquinas, puede acelerar el propio proceso de degeneración de la enfermedad. Actualmente, no existen terapias efectivas para el tratamiento de la retinosis pigmentaria, por lo que el objetivo general de esta tesis es abordar diferentes estrategias farmacológicas para el tratamiento de la enfermedad, intentando actuar sobre los diferentes procesos que ocurren durante el proceso de degeneración retiniana y ralentizar así su avance. Para ello, en primer lugar, corroboramos la presencia de marcadores inflamatorios en pacientes y en ratones con retinosis pigmentaria. A continuación, evaluamos el efecto de la administración intravítrea de Adalimumab, un anticuerpo anti-TNFα, sobre la degeneración retiniana en un modelo murino de retinosis pigmentaria, el ratón rd10, profundizando en los mecanismos de muerte implicados en el proceso de degeneración. Los estudios in vitro sugieren que el TNFα induce la activación de las poli (ADP) ribosa polimerasas (PARPs) y de caspasas, el aumento de la proteína RIPK3 (receptor-interacting protein) y la disminución de RIPK1 en fotorreceptores de ratón. Los estudios in vivo sugieren que la muerte celular en la retina de los ratones está medida por activación de PARP y del inflamasoma NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3), y, en menor medida, por los mecanismos dependientes de caspasas a día postnatal 23. El tratamiento con Adalimumab intravítreo reduce la degeneración retiniana, disminuyendo la activación de PARP, de la microglía y del inflamasoma NLRP3. Además, con las inyecciones intravítreas conseguimos aumentar la ventana terapéutica con respecto a la administración intraperitoneal, pues el efecto neuroprotector del tratamiento se observa durante más tiempo en los ratones. En tercer lugar, evaluamos el efecto de la estabilización del factor 1 de transcripción inducible por hipoxia 1 alfa (HIF-1α) en el ratón rd10. Los resultados de este estudio muestran una disminución generalizada de la proteína HIF-1α y sus genes diana, lo que sugiere que la retina se encuentra expuesta a un ambiente hiperóxico durante el proceso de degeneración. El tratamiento con dimetiloxalil glicina (DMOG) disminuye la degeneración y la inflamación en la retina de los ratones, demostrando así el efecto neuroprotector de la estabilización de HIF-1α sobre los procesos de degeneración retiniana en etapas tempranas de la retinosis pigmentaria. Por último, evaluamos el efecto sobre el estado antioxidante-oxidante y la función visual de pacientes con retinosis pigmentaria, de la administración oral de una mezcla de nutracéuticos antioxidantes. Basalmente observamos un desequilibrio del estado redox ocular y en menor grado sistémico. El tratamiento con la mezcla de nutracéuticos antioxidantes durante dos años, evita el empeoramiento de la función visual y produce una ligera mejoría del estado redox ocular, aunque no observamos efecto significativo sobre los marcadores del estado redox en sangre. En conclusión, nuestros resultados confirman que existen alteraciones en el sistema antioxidante, los procesos inflamatorios y la biodisponibilidad de oxígeno a nivel ocular, implicadas en la patogénesis de la retinosis pigmentaria. Además, sugieren que reduciendo algunos de estos procesos como la inflamación o el estrés oxidativo es posible ralentizar la progresión de la degeneración de la retina, con la ventaja de ser estrategias farmacológicas independientes del defecto genético causante de la retinosis pigmentaria.Retinitis pigmentosa comprises of a group of inherited retinal dystrophies, characterized by the progressive and irreversible loss of vision due to the death of photoreceptor cells. It is a rare disease, which is the main genetic cause of blindness, with a prevalence of one affected per 4000 inhabitants. While retinal degeneration begins with the death of the rods due to genetic mutations, the death of the cones appears to be the result of progressive oxidative damage, inflammation, and metabolic imbalance, influenced by the release of toxic substances by photoreceptors and other surrounding cells. Rod death results in the appearance of the first symptoms of the disease, such as night blindness and tunnel vision, and cone death ends up causing the loss of central vision. Photoreceptors are particularly susceptible to oxidative damage and lipid peroxidation due to their high metabolic rate and the environmental risks to which they are exposed. Different evidence in experimental models and patients with retinitis pigmentosa show alterations in the antioxidant-oxidant status. Moreover, the presence of oxidative stress could be correlated with a worse visual function. Photoreceptor cells are the main consumers of oxygen in the retina. According to this oxidative hypothesis, rod death during the early stages of the disease would cause an increase in the concentration of oxygen or hyperoxia, which would produce oxidative stress. This oxidative stress would exacerbate rod death and contribute to cone death. A strong implication of inflammation has been also proposed for the progression of the disease. Inflammation would lead to the activation of microglia that releases pro-inflammatory cytokines, such as tumor necrosis factor (TNFα), among other signalling molecules. Prolonged maintenance of high levels of these molecules, especially cytokines can speed up the process of disease degeneration itself. Currently, there are no effective therapies for the treatment of retinitis pigmentosa. Therefore, the main purpose of this thesis is to address different pharmacological approaches acting on the different inflammatory ad oxidative stress processes that occur during the retinal degeneration process to slow down the degeneration. First, we corroborated the presence of inflammatory markers in patients and mice with retinitis pigmentosa. We then evaluated the effect of the intravitreal administration of Adalimumab, an anti-TNFα antibody, on the retinal degeneration of a model of retinitis pigmentosa, the rd10 mouse, delving into the death cell mechanisms involved in the degenerative process. In vitro studies suggest that TNFα induces the activation of poly (ADP) ribose polymerases (PARPs) and caspases, increased RIPK3 (receptor-interacting protein) and decreased RIPK1 in 661W cells (cell line of murine cones). In vivo studies suggest that the photoreceptor cell death is mediated by the activation of PARP and NLRP3 inflammasome (NOD- LRR- and pyrin domain-containing protein 3), and, to a lesser extent, by caspase dependent mechanisms at postnatal day 23 in rd10 mice. Treatment with intravitreal Adalimumab reduced retinal degeneration, decreasing the activation of PARP, microglia and NLRP3 inflammasome. Therefore, a single intravitreal injection of Adalimumab improved the neuroprotective effect previously observed after several intraperitoneal injections, increasing the therapeutic window. Third, we evaluated the effect of the hypoxia-inducible transcription factor 1 alpha (HIF-1α) stabilization in rd10 retinas. The results of this study showed a generalized decrease in the HIF-1α protein and its target genes, suggesting that the retina is exposed to a hyperoxic environment during the degenerative process. Treatment with dimethylhoxalyl glycine (DMOG) slowed down the degeneration and inflammation in rd10 retina at postnatal day 18 and lesser to extent at postnatal day 23, thus demonstrating the neuroprotective effect of HIF-1α stabilization at early stages of retinitis pigmentosa. Finally, we evaluated the effect of oral administration of a mixture of nutraceutical with antioxidant properties on the ocular redox status and the visual function of patients with retinitis pigmentosa. The baseline values of several markers of redox status indicated an imbalance of the ocular redox status and, in a lesser extent to systemic redox status in patients compared to healthy subjects. The treatment with the mixture of nutraceutical for two years, partly prevented the worsening of visual function and produced a slight improvement of the ocular redox status. We did not observe significant effect on the redox status in blood. In conclusion, our results indicate that there are alterations in the antioxidant system, inflammatory processes and the retinal bioavailability of oxygen that would be involved in the pathogenesis of retinitis pigmentosa. In addition, these results suggest that it is possible to slow down the retinal degeneration by reducing, at least in part, some of these inflammatory or oxidative stress processes. These therapeutic approaches take the advantage of being strategies independent of the genetic defect causing retinitis pigmentosa

Nutraceutical Supplementation Ameliorates Visual Function, Retinal Degeneration, and Redox Status in rd10 Mice

Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies characterized by progressive degeneration of photoreceptor cells. Ocular redox status is altered in RP suggesting oxidative stress could contribute to their progression. In this study, we investigated the effect of a mixture of nutraceuticals with antioxidant properties (NUT) on retinal degeneration in rd10 mice, a model of RP. NUT was orally administered to rd10 mice from postnatal day (PD) 9 to PD18. At PD18 retinal function and morphology were examined by electroretinography (ERG) and histology including TUNEL assay, immunolabeling of microglia, Müller cells, and poly ADP ribose polymers. Retinal redox status was determined by measuring the activity of antioxidant enzymes and some oxidative stress markers. Gene expression of the cytokines IL-6, TNFα, and IL-1β was assessed by real-time PCR. NUT treatment delayed the loss of photoreceptors in rd10 mice partially preserving their electrical responses to light stimuli. Moreover, it ameliorated redox status and reduced inflammation including microglia activation, upregulation of cytokines, reactive gliosis, and PARP overactivation. NUT ameliorated retinal functionality and morphology at early stages of RP in rd10 mice. This formulation could be useful as a neuroprotective approach for patients with RP in the future

Infliximab reduces Zaprinast-induced retinal degeneration in cultures of porcine retina

Background: cGMP-degrading phosphodiesterase 6 (PDE6) mutations cause around 4 to 5% of retinitis pigmentosa (RP), a rare form of retinal dystrophy. Growing evidence suggests that inflammation is involved in the progression of RP. The aims of this study were to corroborate the presence of high TNFα concentration in the eyes of RP patients and to evaluate whether the blockade of TNFα with Infliximab, a monoclonal anti-TNFα antibody, prevented retinal degeneration induced by PDE6 inhibition in cultures of porcine retina. Methods: Aqueous humor from 30 patients with RP and 13 healthy controls were used to quantify the inflammatory mediators IL-6, TNFα, IL-1β, IL-10 by a multiplex enzyme-linked immunosorbent assay (ELISA) system. Retinal explants from pig were exposed to Zaprinast, a PDE6 inhibitor, for 24 hours in the absence or the presence of Infliximab. Cell death was evaluated by TUNEL assay. The number and distribution of caspase-3 positive cells, indirect poly(ADP)ribose polymerase (PARP) activation and glial fibrillary acidic protein (GFAP) content were visualized by immunolabeling. Antioxidant total capacity, nitrites and thiobarbituric acid reactive substances (TBARS) formation were determined to evaluate antioxidant-oxidant status. Results: IL-6 and TNFα concentrations were higher in the aqueous humor of RP patients than in controls. Infliximab prevented retinal degeneration, as judging by the reduced presence of TUNEL-positive cells, the reduction of caspase-3 activation and also reduction of glial activation, in an ex vivo model of porcine retina. Additionally, Infliximab partially reduced oxidative stress in retinal explants exposed to Zaprinast. Conclusions: Inflammatory mediators IL-6 and TNFα were elevated in the aqueous humor of RP patients corroborating previous studies suggesting sustained chronic inflammation. Our study suggests that TNFα is playing an important role in cell death in an ex vivo model of retinal degeneration by activating different cell pathways at different cell layers of the retina that should be further studied.This work was supported by the European Regional Development Fund, Institute of Health Carlos III, PI10/01825 and PI12/0481 from the Spanish Ministry of Economy and Competitiveness (MEC). CIBERER is an initiative of the Institute of Health Carlos III from the MEC. Regina Rodrigo has a research-contract SNS Miguel Servet (CP09/118) from Institute of Health Carlos III.Medicin

Adalimumab reduces photoreceptor cell death in a mouse model of retinal degeneration

Growing evidence suggests that inflammation is involved in the progression of retinitis pigmentosa (RP) both in patients and in animal models. The aim of this study was to investigate the effect of Adalimumab, a monoclonal anti-TNFα antibody, on retinal degeneration in a murine model of human autosomal recessive RP, the rd10 mice at postnatal day (P) 18. In our housing conditions, rd10 retinas were seriously damaged at P18. Adalimumab reduced photoreceptor cell death, as determined by scoring the number of TUNEL-positive cells. In addition, nuclear poly (ADP) ribose (PAR) content, an indirect measure of PAR polymerase (PARP) activity, was also reduced after treatment. The blockade of TNFα ameliorated reactive gliosis, as visualized by decreased GFAP and IBA1 immunolabelling (Müller cell and microglial markers, respectively) and decreased up-regulation of TNFα gene expression. Adalimumab also improved antioxidant response by restoring total antioxidant capacity and superoxide dismutase activity. Finally, we observed that Adalimumab normalized energetic and metabolic pattern in rd10 mouse retinas. Our study suggests that the TNFα blockade could be a successful therapeutic approach to increase photoreceptor survival during the progression of RP. Further studies are needed to characterize its effect along the progression of the diseaseThis work was supported by the European Regional Development Fund, Institute of Health Carlos III, PI12/0481, SAF2013-41059-R and SAF2013-41945 from the Spanish Ministry of Economy and Competitiveness (MEC). CIBERER is an initiative of the Institute of Health Carlos III from the MEC. Regina Rodrigo has a research-contract SNS Miguel Servet (CP09/118) from Institute of Health Carlos II

NUTRARET: Effect of 2-Year Nutraceutical Supplementation on Redox Status and Visual Function of Patients With Retinitis Pigmentosa: A Randomized, Double-Blind, Placebo-Controlled Trial

Oxidative stress plays a major role in the pathogenesis of retinitis pigmentosa (RP). The main goal of this study was to evaluate the effect of 2-year nutritional intervention with antioxidant nutraceuticals on the visual function of RP patients. Secondly, we assessed how nutritional intervention affected ocular and systemic redox status. We carried out a randomized, double-blind, placebo-controlled study. Thirty-one patients with RP participated in the study. RP patients randomly received either a mixture of nutraceuticals (NUT) containing folic acid, vitamin B6, vitamin A, zinc, copper, selenium, lutein, and zeaxanthin or placebo daily for 2 years. At baseline and after 2- year of the nutritional supplementation, visual function, dietetic-nutritional evaluations, serum concentration of nutraceuticals, plasma and aqueous humor concentration of several markers of redox status and inflammation were assessed. Retinal function and structure were assessed by multifocal electroretinogram (mfERG), spectral domain-optical coherence tomography (SD-OCT) and automated visual field (VF) tests. Nutritional status was estimated with validated questionnaires. Total antioxidant capacity, extracellular superoxide dismutase (SOD3), catalase (CAT), and glutathione peroxidase (GPx) activities, protein carbonyl adducts (CAR) content, thiobarbituric acid reactive substances (TBARS) formation (as indicator of lipid peroxidation), metabolites of the nitric oxide (NOX) and cytokine (interleukin 6 and tumor necrosis factor alpha) concentrations were assessed by biochemical and immunological techniques in aqueous humor or/and blood. Bayesian approach was performed to determine the probability of an effect. Region of practical equivalence (ROPE) was used. At baseline, Bayesian analysis revealed a high probability of an altered ocular redox status and to a lesser extent systemic redox status in RP patients compared to controls. Twenty-five patients (10 in the treated arm and 15 in the placebo arm) completed the nutritional intervention. After 2 years of supplementation, patients who received NUT presented better retinal responses (mfERG responses) compared to patients who received placebo. Besides, patients who received NUT showed better ocular antioxidant response (SOD3 activity) and lower oxidative damage (CAR) than those who received placebo. This study suggested that long-term NUT supplementation could slow down visual impairment and ameliorate ocular oxidative stress.This work was supported by the Spanish Ministry of Economy, Industry, and Competitiveness (MINECO) Carlos III Health Institute (ISCIII) (Grant numbers: PI15/00052 and PI18/00252) and co-funded by the European Regional Development Fund (FEDER)/European Social Fund “A way to make Europe”/”Investing in your future.” It was also supported by the IIS La Fe-UV PROGRAMA VLC-BIOMED-I (NUTRARET) and by RETINA COMUNIDAD VALENCIANA. LO-G had an ISCIIIMedicin

Plantes ornamentals tòxiques

Facultat de Farmàcia, Universitat de Barcelona. Ensenyament: Grau de Farmàcia, Assignatura: Plantes medicinals, etnobotànica i bioprospecció, Curs: 2013-2014, Coordinadors: Carles Benedí i Joan SimonAquesta obra és el resultat de la tasca col·laborativa feta pels estudiants de l’assignatura optativa de l’ensenyament de Farmàcia «Plantes Medicinals, Etnobotànica i Bioprospecció» del curs 2013-2014. El seu contingut se centra en unes monografies didàctiques sobre quinze plantes ornamentals tòxiques, per a les quals es detalla la nomenclatura, l’origen i la distribució geogràfica, la descripció botànica, la toxicitat i la bibliografia utilitzada

Salud de los trabajadores

Actividad física y su relación con los factores de riesgo cardiovascular de carteros chilenosAnálisis de resultados: riesgos psicosociales en el trabajo Suceso-Istas 21 en Cesfam QuellónAusentismo laboral por enfermedades oftalmológicas, Chile 2009Brote de diarreas por norovirus, posterremoto-tsunami, Constitución, Región del MauleCalidad de vida en profesionales de la salud pública chilenaCaracterización del reposo laboral en personal del SSMN durante el primer semestre de 2010Concentración de nicotina en pelo en trabajadores no fumadores expuestos a humo de tabaco ambientalCondiciones de trabajo y bienestar/malestar docente en profesores de enseñanza media de SantiagoDisfunción auditiva inducida por exposición a xilenoErgonomía aplicada al estudio del síndrome de dolor lumbar en el trabajoEstimación de la frecuencia de factores de riesgo cardiovascular en trabajadores de una empresa mineraExposición a plaguicidas inhibidores de la acetilcolinesterasa en Colombia, 2006-2009Factores de riesgo y daños de salud en conductores de una empresa peruana de transporte terrestre, 2009Las consecuencias de la cultura en salud y seguridad ocupacional en una empresa mineraPercepción de cambios en la práctica médica y estrategias de afrontamientoPercepción de la calidad de vida en la Universidad del BiobíoPesos máximos aceptables para tareas de levantamiento manual de carga en población laboral femeninaRiesgo coronario en trabajadores mineros según la función de Framingham adaptada para la población chilenaTrastornos emocionales y riesgo cardiovascular en trabajadores de la salu

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat