REDOX Balance in Oligodendrocytes Is Important for Zebrafish Visual System Regeneration.

Zebrafish (Danio rerio) present continuous growth and regenerate many parts of their body after an injury. Fish oligodendrocytes, microglia and astrocytes support the formation of new connections producing effective regeneration of the central nervous system after a lesion. To understand the role of oligodendrocytes and the signals that mediate regeneration, we use the well-established optic nerve (ON) crush model. We also used sox10 fluorescent transgenic lines to label fully differentiated oligodendrocytes. To quench the effect of reactive oxygen species (ROS), we used the endogenous antioxidant melatonin. Using these tools, we measured ROS production by flow cytometry and explored the regeneration of the optic tectum (OT), the response of oligodendrocytes and their mitochondria by confocal microscopy and Western blot. ROS are produced by oligodendrocytes 3 h after injury and JNK activity is triggered. Concomitantly, there is a decrease in the number of fully differentiated oligodendrocytes in the OT and in their mitochondrial population. By 24 h, oligodendrocytes partially recover. Exposure to melatonin blocks the changes observed in these oligodendrocytes at 3 h and increases their number and their mitochondrial populations after 24 h. Melatonin also blocks JNK upregulation and induces aberrant neuronal differentiation in the OT. In conclusion, a proper balance of ROS is necessary during visual system regeneration and exposure to melatonin has a detrimental impact.

Improving emergency department care of infants with acute bronchiolitis by reducing the use of unrecommended drugs: a quality-of-care initiative in a Spanish autonomous community. / Iniciativa de mejora para reducir el uso de fármacos no recomendados en el manejo de lactantes con bronquiolitis aguda en los servicios de urgencias de una comunidad autónoma.

OBJECTIVES: To evaluate the impact of a quality-of-care improvement program implemented in emergency departments (EDs) in a Spanish autonomous community with the aim of reducing the use of unrecommended drugs when treating infants for acute bronchiolitis. MATERIAL AND METHODS: Before-after quasi-experimental intervention study. We retrospectively included infants aged 12 months or less who were treated for acute bronchiolitis in 24 Spanish national health system hospital EDs in December during 2 epidemic periods: in 2018, before implementing the program, and in 2019, after implementation. Data collected included epidemiologic information, clinical and care details, and clinical course. The program consisted of providing informative material and training sessions before the epidemic period started. RESULTS: A total of 7717 episodes (4007 in 2018 and 2710 in 2019) were identified. Epidemiologic and clinical characteristics did not differ between the 2 periods. ED use of the following treatments decreased between the 2 periods: salbutamol, from 29.4% (95% CI, 28.8%-30.8%) in 2018 to 10.6% (95% CI, 9.6%-11.6%) in 2019; epinephrine from 6.0% (95% CI, 5.3%-6.8%) to 0.9% (95% CI, 0.7%-1.3%); and hypertonic saline solution fell from 8.2% (95% CI, 7.3%-9.1%) to 2.1% (95% CI, 1.7%-2.6%) (P.001, all comparisons). Prescriptions for salbutamol on discharge fell from 38.7% (95% CI, 36.9%-40.4%) to 10.6% (95% CI, 9.6%-11.6%) (P.001). Admissions and readmissions did not change, and the median time (interquartile range) spent in the ED fell from 81 (44-138) minutes to 66 (37-127) minutes (P.001). CONCLUSION: The quality-of-care improvement initiative was able to decrease the number of unrecommended therapeutic interventions for acute bronchiolitis. However, we identified great variations between EDs, suggesting that training and assessment of impact should continue.

OBJETIVO: Evaluar el impacto de una iniciativa de mejora realizada en los servicios de urgencias (SU) de una comunidad autónoma para reducir el uso de fármacos no recomendados en lactantes con bronquiolitis aguda (BA). METODO: Estudio cuasi-experimental analítico del tipo "antes y después de una intervención". Se incluyeron de forma retrospectiva todas las BA en niños # 12 meses atendidas en los SU de 24 hospitales públicos durante el mes de diciembre de dos periodos epidémicos: 2018 (preintervención) y 2019 (postintervención). Se recogieron variables epidemiológicas, clínicas, asistenciales y evolutivas. La intervención consistió en difundir material informativo y realizar actividades formativas previas al periodo epidémico. RESULTADOS: Se incluyeron 7.717 episodios (2018: 4.007 y 2019: 3.710). No existieron diferencias en las características epidemiológicas y clínicas. El empleo de salbutamol en los SU descendió del 29,4% [intervalo de confianza del 95% (IC 95%): 28,8-30,8] en 2018 al 10,6% (IC 95%: 9,6-11,6) en 2019 (p 0,001), el de adrenalina del 6,0% (IC 95%: 5,3-6,8) al 0,9% (IC 95%: 0,7-1,3) y el de suero salino hipertónico del 8,2% (IC 95%: 7,3-9,1) al 2,1% (IC 95%: 1,7-2,6) (p 0,001). La prescripción al alta de salbutamol se redujo del 38,7% (IC 95%: 36,9-40,4) al 10,6% (IC 95%: 9,6-11,6) (p 0,001). La tasa de ingreso y la tasa de readmisión no cambiaron y la mediana de tiempo de estancia en los SU se redujo 81 minutos [rango intercuartil (RIC) 44-138] a 66 (RIQ: 37-127) (p 0,001). CONCLUSIONES: La iniciativa de mejora ha conseguido disminuir la tasa de intervenciones terapéuticas no indicadas en BA. Sin embargo, existe una gran variabilidad entre los diferentes SU por lo que la estrategia y la medición de su impacto deben mantenerse en el tiempo.

Iniciativa de mejora para reducir el uso de fármacos no recomendados en el manejo de lactantes con bronquiolitis aguda en los servicios de urgencias de una comunidad autónoma / Improving emergency department care of infants with acute bronchiolitis by reducing the use of unrecommended drugs: a quality-of-care initiative in a Spanish autonomous community

Objetivo. Evaluar el impacto de una iniciativa de mejora realizada en los servicios de urgencias (SU) de una comunidad autónoma para reducir el uso de fármacos no recomendados en lactantes con bronquiolitis aguda (BA).Método. Estudio cuasi-experimental analítico del tipo “antes y después de una intervención”. Se incluyeron de forma retrospectiva todas las BA en niños # 12 meses atendidas en los SU de 24 hospitales públicos durante el mes de diciembre de dos periodos epidémicos: 2018 (preintervención) y 2019 (postintervención). Se recogieron variables epidemiológicas, clínicas, asistenciales y evolutivas. La intervención consistió en difundir material informativo y realizar actividades formativas previas al periodo epidémico.Resultados. Se incluyeron 7.717 episodios (2018: 4.007 y 2019: 3.710). No existieron diferencias en las características epidemiológicas y clínicas. El empleo de salbutamol en los SU descendió del 29,4% [intervalo de confianza de 95% (IC 95%): 28,8-30,8] en 2018 al 10,6% (IC 95%: 9,6-11,6) en 2019 (p < 0,001), el de adrenalina del 6,0% (IC 95%: 5,3-6,8) al 0,9% (IC 95%: 0,7-1,3) y el de suero salino hipertónico del 8,2% (IC 95%: 7,3-9,1) al 2,1% (IC 95%: 1,7-2,6) (p < 0,001). La prescripción al alta de salbutamol se redujo del 38,7% (IC 95%: 36,9-40,4) al 10,6% (IC 95%: 9,6-11,6) (p < 0,001). La tasa de ingreso y la tasa de readmisión no cambiaron y la mediana de tiempo de estancia en los SU se redujo 81 minutos [rango intercuartil (RIC) 44-138] a 66 (RIQ: 37-127) (p < 0,001).Conclusiones. La iniciativa de mejora ha conseguido disminuir la tasa de intervenciones terapéuticas no indicadas en BA. Sin embargo, existe una gran variabilidad entre los diferentes SU por lo que la estrategia y la medición de su impacto deben mantenerse en el tiempo. (AU)

Objective. To evaluate the impact of a quality-of-care improvement program implemented in emergency departments (EDs) in a Spanish autonomous community with the aim of reducing the use of unrecommended drugs when treating infants for acute bronchiolitis. Methods. Before-after quasi-experimental intervention study. We retrospectively included infants aged 12 months or less who were treated for acute bronchiolitis in 24 Spanish national health system hospital EDs in December during 2 epidemic periods: in 2018, before implementing the program, and in 2019, after implementation. Data collected included epidemiologic information, clinical and care details, and clinical course. The program consisted of providing informative material and training sessions before the epidemic period started. Results. A total of 7717 episodes (4007 in 2018 and 2710 in 2019) were identified. Epidemiologic and clinical characteristics did not differ between the 2 periods. ED use of the following treatments decreased between the 2 periods: salbutamol, from 29.4% (95% CI, 28.8%-30.8%) in 2018 to 10.6% (95% CI, 9.6%-11.6%) in 2019; epinephrine from 6.0% (95% CI, 5.3%-6.8%) to 0.9% (95% CI, 0.7%-1.3%); and hypertonic saline solution fell from 8.2% (95% CI, 7.3%-9.1%) to 2.1% (95% CI, 1.7%-2.6%) (P<.001, all comparisons). Prescriptions for salbutamol on discharge fell from 38.7% (95% CI, 36.9%-40.4%) to 10.6% (95% CI, 9.6%-11.6%) (P<.001). Admissions and readmissions did not change, and the median time (interquartile range) spent in the ED fell from 81 (44-138) minutes to 66 (37-127) minutes (P<.001). Conclusions. The quality-of-care improvement initiative was able to decrease the number of unrecommended therapeutic interventions for acute bronchiolitis. However, we identified great variations between EDs, suggesting that training and assessment of impact should continue. (AU)

Oligodendrocyte origin and development in the zebrafish visual system.

Oligodendrocytes are the myelinating cells in the central nervous system. In birds and mammals, the oligodendrocyte progenitor cells (OPCs) originate in the preoptic area (POA) of the hypothalamus. However, it remains unclear in other vertebrates such as fish. Thus, we have studied the early progression of OPCs during zebrafish visual morphogenesis from 2 days post fertilization (dpf) until 11 dpf using the olig2:EGFP transgenic line; and we have analyzed the differential expression of transcription factors involved in oligodendrocyte differentiation: Sox2 (using immunohistochemistry) and Sox10 (using the transgenic line sox10:tagRFP). The first OPCs (olig2:EGFP/Sox2) were found at 2 dpf in the POA. From 3 dpf onwards, these olig2:EGFP/Sox2 cells migrate to the optic chiasm, where they invade the optic nerve (ON), extending toward the retina. At 5 dpf, olig2:EGFP/Sox2 cells in the ON also colocalize with sox10:tagRFP. When olig2:EGFP cells differentiate and present more projections, they become positive only for sox10:tagRFP. olig2:EGFP/sox10: tagRFP cells ensheath the ON by 5 dpf when they also become positive for a myelin marker, based on the mbpa:tagRFPt transgenic line. We also found olig2:EGFP cells in other regions of the visual system. In the central retina at 2 dpf, they are positive for Sox2 but later become restricted to the proliferative germinal zone without this marker. In the ventricular areas of the optic tectum, olig2:EGFP cells present Sox2 but arborized ones sox10:tagRFP instead. Our data matches with other models, where OPCs are specified in the POA and migrate to the ON through the optic chiasm.

Urinary Tract Infection in Pediatrics: Study of Uropathogens and Their Resistance in a Madrid Hospital.

INTRODUCTION: Resistance to antibiotics is a growing problem with repercussions on the choice of first-line treatment in urinary tract infection (UTI) in childhood. OBJECTIVES: To know the current pattern of antibiotic susceptibility/resistance of the most frequent germs that cause UTI in our healthcare area. Secondary objective is to know the evolution of these patterns over time. PATIENTS AND METHODS: A cross-sectional retrospective study of UTI episodes in a first-level hospital in two periods: 1st January 2008-31th December 2010 and 1st January 2017-31th December 2019 through a review of medical records, recording the following variables: Age, sex, fever, hospital admission, uropathy/bladder dysfunction, antibiotic prophylaxis. RESULTS: First period: 174 UTI episodes (156 patients); Second period: 266 UTI episodes (218 patients). The most frequently isolated germ was E. coli, but in patients with uropathy or bladder dysfunction, the percentage of different germs is greater. A significant increase in resistance to amoxicillin/clavulanate (from 12.2 to 24%) is observed between both periods, it remains stable and in an acceptable range for gentamicin, cotrimoxazole and slightly increases to first-generation cephalosporins. In patients with uropathy/bladder dysfunction, resistance to all these antibiotics is significantly increased. CONCLUSIONS: The increased resistance of the most frequent uropathogens in the UTI of the pediatric population of our healthcare area to amoxicillin/clavulanate makes it unsuitable as empirical therapy. First-generation cephalosporins are an adequate alternative in patients without risk factors.

Urinary Tract Infection in Pediatrics: Study of Uropathogens and Their Resistance in a Madrid Hospital

Introduction: Resistance to antibiotics is a growing problem with repercussions on the choice of first-line treatment in urinary tract infection (UTI) in childhood. Objectives: To know the current pattern of antibiotic susceptibility/resistance of the most frequent germs that cause UTI in our healthcare area. Secondary objective is to know the evolution of these patterns over time. Patients and Methods: A cross-sectional retrospective study of UTI episodes in a first-level hospital in two periods: 1st January 2008-31th December 2010 and 1st January 2017-31th December 2019 through a review of medical records, recording the following variables: Age, sex, fever, hospital admission, uropathy/bladder dysfunction, antibiotic prophylaxis. Results: First period: 174 UTI episodes (156 patients); Second period: 266 UTI episodes (218 patients). The most frequently isolated germ was E. coli, but in patients with uropathy or bladder dysfunction, the percentage of different germs is greater. A significant increase in resistance to amoxicillin/clavulanate (from 12.2 to 24%) is observed between both periods, it remains stable and in an acceptable range for gentamicin, cotrimoxazole and slightly increases to first-generation cephalosporins. In patients with uropathy/bladder dysfunction, resistance to all these antibiotics is significantly increased. Conclusions: The increased resistance of the most frequent uropathogens in the UTI of the pediatric population of our healthcare area to amoxicillin/clavulanate makes it unsuitable as empirical therapy. First-generation cephalosporins are an adequate alternative in patients without risk factors (AU)

Introducción: La resistencia a antibióticos es unproblema creciente con repercusión en la elección deltratamiento empírico en la infección del tracto urinario(ITU) en la infancia.Objetivos: Conocer cómo ha evolucionado la incidencia de uropatógenos causantes de ITU en poblaciónpediátrica y su patrón de resistencia antibiótica en el área11 de salud de la Comunidad de Madrid. Secundariamente,patrón de resistencia actual.Materiales y Métodos: Estudio de corte transversal retrospectivo de los episodios de ITU de un hospitalde Nivel I en dos periodos: 1 enero 2008 a 31 diciembre2010 y 1 enero 2017 a 31 diciembre 2019. Se recogió:Edad, sexo, fiebre, uropatía/disfunción vesical, profilaxisantibiótica, microorganismo aislado y su antibiograma. Serealizó estudio descriptivo de todas las variables recogidas ycomparación de proporciones independientes, utilizando laprueba chi cuadrado,tomando como variable de agrupación cada periodo. El análisis estadístico fue realizado con elprograma EPIDAT v 4.2.Resultados: Primer periodo: 174 episodios de ITU(156 pacientes); Segundo periodo: 266 episodios de ITU(218 pacientes). El germen más frecuentemente aisladofue E. coli, siendo mayor el aislamiento de gérmenes distintos en pacientes urópatas/disfunción vesical. Se observa un aumento significativo de la resistencia a amoxicilina/clavulánico, se mantiene estable y en rango aceptablepara gentamicina, cotrimoxazol y aumenta levemente a cefalosporinas de primera generación. En los pacientes conuropatía/disfunción vesical las resistencias a todos estos antibióticos se incrementansignificativamente.Conclusiones: El aumento de la resistencia de losuropatógenos más frecuentes en la ITU de la poblaciónpediátrica a amoxicilina/clavulánico del área sanitaria estudiada, lo hace no apto como terapia empírica. Las cefalosporinas de primera generación suponen una adecuadaalternativa en pacientes sin factores de riesgo (AU)

Scribble basal polarity acquisition in RPE cells and its mislocalization in a pathological AMD-like model.

Apicobasal polarity is a hallmark of retinal pigment epithelium cells and is required to perform their functions; however, the precise roles of the different proteins that execute polarity are still poorly understood. Here, we have studied the expression and location of Scribble, the core member of the polarity basal protein complex in epithelial-derived cells, in human and mouse RPE cells in both control and pathological conditions. We found that Scribble specifically localizes at the basolateral membrane of mouse and human RPE cells. In addition, we observed an increase in the expression of Scribble during human RPE development in culture, while it acquires a well-defined basolateral pattern as this process is completed. Finally, the expression and location of Scribble were analyzed in human RPE cells in experimental conditions that mimic the toxic environment suffered by these cells during AMD development and found an increase in Scribble expression in cells that develop a pathological phenotype, suggesting that the protein could be altered in cells under stress conditions, as occurs in AMD. Together, our results demonstrate, for the first time, that Scribble is expressed in both human and mouse RPE and is localized at the basolateral membrane in mature cells. Furthermore, Scribble shows impaired expression and location in RPE cells in pathological conditions, suggesting a possible role for this protein in the development of pathologies, such as AMD.

Doublecortin in the Fish Visual System, a Specific Protein of Maturing Neurons.

Doublecortin (DCX) is a microtubule associated protein, essential for correct central nervous system development and lamination in the mammalian cortex. It has been demonstrated to be expressed in developing-but not in mature-neurons. The teleost visual system is an ideal model to study mechanisms of adult neurogenesis due to its continuous life-long growth. Here, we report immunohistochemical, in silico, and western blot analysis to detect the DCX protein in the visual system of teleost fish. We clearly determined the expression of DCX in newly generated cells in the retina of the cichlid fish Astatotilapia burtoni, but not in the cyprinid fish Danio rerio. Here, we show that DCX is not associated with migrating cells but could be related to axonal growth. This work brings to light the high conservation of DCX sequences between different evolutionary groups, which make it an ideal marker for maturing neurons in various species. The results from different techniques corroborate the absence of DCX expression in zebrafish. In A. burtoni, DCX is very useful for identifying new neurons in the transition zone of the retina. In addition, this marker can be applied to follow axons from maturing neurons through the neural fiber layer, optic nerve head, and optic nerve.

Key Role for CRB2 in the Maintenance of Apicobasal Polarity in Retinal Pigment Epithelial Cells.

Apicobasal polarity is essential for epithelial cell function, yet the roles of different proteins in its completion is not fully understood. Here, we have studied the role of the polarity protein, CRB2, in human retinal pigment epithelial (RPE) cells during polarization in vitro, and in mature murine RPE cells in vivo. After establishing a simplified protocol for the culture of human fetal RPE cells, we studied the temporal sequence of the expression and localization of polarity and cell junction proteins during polarization in these epithelial cells. We found that CRB2 plays a key role in tight junction maintenance as well as in cell cycle arrest. In addition, our studies in vivo show that the knockdown of CRB2 in the RPE affects to the distribution of different apical polarity proteins and results in perturbed retinal homeostasis, manifested by the invasion of activated microglial cells into the subretinal space. Together our results demonstrate that CRB2 is a key protein for the development and maintenance of a polarized epithelium.

Peripherally inserted central venous catheter placed and maintained by a dedicated nursing team for the administration of antimicrobial therapy vs. another type of catheter: a retrospective case-control study / Catéter venoso central de inserción periférica insertado y cuidado por un equipo entrenado de enfermería para la administración de terapia antimicrobiana frente a otro tipo de catéteres: estudio retrospectivo de casos y controles

INTRODUCTION: Data concerning the use of peripherally inserted central catheters (PICC) for the administration of intravenous (IV) antimicrobials in the acute care setting is scarce. METHODS: We performed a single-center retrospective case-control study (1:1). Case subjects were defined as patients who received IV antimicrobial treatment through a PICC line placed and maintained by specifically trained nurses (PICC group). Control subjects were defined as patients who received antimicrobial therapy by a peripheral or a central venous catheter (CVC) (control group). Control subjects were matched by type of antimicrobial, causative microorganism of the infection that was being treated and duration of treatment. An event leading to undesired catheter removal (ELUCR) was defined as any circumstance which lead to the removal of the indwelling catheter other than the completion of the scheduled course of antimicrobial therapy. RESULTS: The study included 50 patients in each group. The total follow-up time was 1376 catheter-days for the PICC group and 1362 catheter-days for the control group. We observed a significantly lower incidence of ELUCR in the PICC group (0.2 versus 7.7 events per 100 catheter-days; P < 0.001). When the incidence of ELUCR was analyzed according to the duration of indwelling catheterisation for each type of catheter (divided into one-week intervals), differences between both groups were also significant (P-values ≤ 0.001 for the first three weeks of treatment). During the second week of IV treatment, only one patient in the PICC group (2.1%) developed an ELUCR compared to 19 (38.8%) in the control group (P < 0.001). CONCLUSIONS: A PICC placed and maintained by a dedicated nursing team is an excellent alternative to peripheral venous catheters or CVCs for administrating antimicrobial therapy for both short and long periods of treatment

INTRODUCCIÓN: Existe escasa información disponible sobre el empleo de catéteres venosos centrales de inserción periférica (PICC en sus siglas en inglés) para la administración de antimicrobianos por vía intravenosa (IV) en la atención a pacientes con procesos agudos. MÉTODOS: Realizamos un estudio unicéntrico retrospectivo de casos y controles (1:1). Los casos estaban constituidos por pacientes que recibieron tratamiento antimicrobiano IV a través de un catéter tipo PICC que fue insertado y cuidado por un equipo de enfermería especialmente entrenado a tal efecto (grupo PICC). Los controles estaban constituidos por pacientes que recibieron el tratamiento antimicrobiano a través de un catéter venoso periférico o a través de un catéter venoso central (CVC) (grupo control). Los controles fueron emparejados con los casos considerando el tipo de antimicrobiano administrado, el microorganismo causal de la infección que se estaba tratando y la duración del tratamiento. Se definió como un evento que condujo a la retirada no deseada del catéter (ECRDC) a cualquier circunstancia que obligara a la retirada del catéter insertado antes del tiempo programado para completar el tratamiento antimicrobiano establecido. RESULTADOS: El estudio incluyó 50 pacientes en cada grupo. El tiempo total de seguimiento fue de 1.376 días de catéter en el grupo PICC y de 1.362 días de catéter en el grupo control. Se observó una incidencia de ECRDC significativamente menor en el grupo PICC que en el grupo control (0,2 versus 7,7 eventos por cada 100 días de catéter; P < 0,001). Cuando la incidencia de ECRDC se analizó según la duración del tiempo de inserción de cada tipo de catéter (dividido en intervalos de una semana), se pudo constatar que las diferencias entre ambos grupos también eran significativas (P ≤ 0.001 para las tres primeras semanas de tratamiento). Durante la segunda semana de tratamiento IV, solamente un paciente en el grupo PICC (2,1%) desarrolló un ECRDC en comparación con 19 (38,8%) en el grupo control (P (P < 0,001). CONCLUSIONES: Un catéter tipo PICC insertado y cuidado por un equipo de enfermería entrenado es una excelente alternativa a los catéteres venosos periféricos o a los CVC para la administración de antimicrobianos tanto para periodos cortos como para periodos largos de tiempo

Peripherally inserted central venous catheter placed and maintained by a dedicated nursing team for the administration of antimicrobial therapy vs. another type of catheter: a retrospective case-control study.

INTRODUCTION: Data concerning the use of peripherally inserted central catheters (PICC) for the administration of intravenous (IV) antimicrobials in the acute care setting is scarce. METHODS: We performed a single-center retrospective case-control study (1:1). Case subjects were defined as patients who received IV antimicrobial treatment through a PICC line placed and maintained by specifically trained nurses (PICC group). Control subjects were defined as patients who received antimicrobial therapy by a peripheral or a central venous catheter (CVC) (control group). Control subjects were matched by type of antimicrobial, causative microorganism of the infection that was being treated and duration of treatment. An event leading to undesired catheter removal (ELUCR) was defined as any circumstance which lead to the removal of the indwelling catheter other than the completion of the scheduled course of antimicrobial therapy. RESULTS: The study included 50 patients in each group. The total follow-up time was 1376 catheter-days for the PICC group and 1362 catheter-days for the control group. We observed a significantly lower incidence of ELUCR in the PICC group (0.2 versus 7.7 events per 100 catheter-days; P<0.001). When the incidence of ELUCR was analyzed according to the duration of indwelling catheterisation for each type of catheter (divided into one-week intervals), differences between both groups were also significant (P-values≤0.001 for the first three weeks of treatment). During the second week of IV treatment, only one patient in the PICC group (2.1%) developed an ELUCR compared to 19 (38.8%) in the control group (P<0.001). CONCLUSIONS: A PICC placed and maintained by a dedicated nursing team is an excellent alternative to peripheral venous catheters or CVCs for administrating antimicrobial therapy for both short and long periods of treatment.

Sox2 expression in the visual system of two teleost species.

The visual system of teleost fish shows growth and regeneration capacities during the entire animal's life. Thus, the visual system of adult fish serves as a model for studying neurogenesis in the vertebrate central nervous system (CNS). Our study focused on the expression pattern of Sox2 in the fish visual system. Sox2 is a transcription factor known for its function in keeping stem cell properties, and as a regulator of cell fate during development, especially in the visual system. We used two different fish species: Astatotilapia burtoni and Danio rerio. In the visual system of fish, we identified Sox2 positive cells in the stem cell niche in the peripheral retina, in Müller cells and amacrine cells in the differentiated retina, and glial cells in the optic nerve (ON). We did not observe hardly any Sox2 expression in the optic nerve head (ONH). In the ON, Sox2 positive glial cells were lining the fascicles of new axons. Taking together, the broad spectrum of Sox2 expression indicates that this protein has different functions in the CNS of adult vertebrates. The results suggest that Sox2 has functions associated with the pathway of new axons from the retina. To understand the variety of cell types and subtypes and their plasticity potential in the visual system of fish will be essential to comprehend the growing and regenerating CNS in adult vertebrates.

Subconjunctival injection of mesenchymal stromal cells protects the cornea in an experimental model of GVHD.

PURPOSE: To evaluate the therapeutic effect of subconjunctival injection of human mesenchymal stromal cells (hMSCs) in the cornea of mice with graft versus host disease (GVHD). METHODS: GVHD was induced in mice after hematopoietic stem cell transplantation (HSCT) between MHC-mismatched mouse strains. Subconjunctival injection of hMSCs was applied at day 10 post-HSCT. Infiltration of CD3+ cells in the cornea and epithelial alterations were analyzed by immunofluorescence. Tear was assessed using the PRT test and TearLab Osmolarity System. qPCR was used to evaluate changes in cytokines, Pax6 and Sprr1b expression. To evaluate the effect of irradiation, we analyzed the expression of these genes in TBI mice. RESULTS: Immune cell invasion occurs in mice with GVHD, as shown by the presence of CD3+ cells in the cornea. Interestingly, eyes treated with hMSC did not present CD3+ cells. Tear osmolarity was increased in GVHD eyes, but not in treated eyes. TNFa expression was highly increased in all corneas except in Control and treated eyes. Pax6 in corneal epithelium showed a similar pattern in GVHD and Control mice, and its gene expression was enhanced in GVHD corneas. In contrast, Pax6 was reduced in GVHD + MSC corneas. We also found an increase in SPRR1B staining in GVHD eyes that was lower in GVHD + MSC mice, demonstrating that corneal keratinization is less frequent after treatment with hMSC. CONCLUSIONS: The treatment with hMSCs by subconjunctival injection is effective in reducing corneal inflammation and squamous metaplasia in ocular GVHD (oGVHD). Local treatment with hMSCs is a promising strategy for oGVHD.

Expression and localization of the polarity protein CRB2 in adult mouse brain: a comparison with the CRB1rd8 mutant mouse model.

Acquisition of cell polarization is essential for the performance of crucial functions, like a successful secretion and appropriate cell signaling in many tissues, and it depends on the correct functioning of polarity proteins, including the Crumbs complex. The CRB proteins, CRB1, CRB2 and CRB3, identified in mammals, are expressed in epithelial-derived tissues like brain, kidney and retina. CRB2 has a ubiquitous expression and has been detected in embryonic brain tissue; but currently there is no data regarding its localization in the adult brain. In our study, we characterized the presence of CRB2 in adult mice brain, where it is particularly enriched in cortex, hippocampus, hypothalamus and cerebellum. Double immunofluorescence analysis confirmed that CRB2 is a neuron-specific protein, present in both soma and projections where colocalizes with certain populations of exocytic and endocytic vesicles and with other members of the Crumbs complex. Finally, in the cortex of CRB1rd8 mutant mice that contain a mutation in the Crb1 gene generating a truncated CRB1 protein, there is an abnormal increase in the expression levels of the CRB2 protein which suggests a possible compensatory mechanism for the malfunction of CRB1 in this mutant background.

Assessment of dry eye in a GVHD murine model: Approximation through tear osmolarity measurement.

Dry eye disease is one of the most frequent pathological events that take place in the course of the graft versus host disease (GVHD), and is the main cause of deterioration in quality of life for patients. Thus, demonstration of dry eye signs in murine models of oGVHD is crucial for the validation of these models for the study of the disease. Given the increasing evidence that tear osmolarity is an important player of dry eye disease, our purpose in this study was to validate the use of a reliable method to assess tear osmolarity in mice: the electrical impedance method. Then, we wanted to test its utility with an oGVHD model. Tear volume assessment was also performed, using the phenol red thread test. We found differences in tear osmolarity in mice that received a transplant with cells from bone marrow and spleen (the GVHD group) when compared with mice that only received bone marrow cells (the BM group) at day 7 (362 ± 8 mOsm/l and 345 ± 9 mOsm/l respectively; P < 0.01) and day 21 (348 ± 19 mOsm/l vs. 326 ± 15 mOsm/l; P < 0.05). We found also differences in tear volume at day 14 (2.30 ± 0.61 mm in oGVHD group and 2.89 ± 0.62 mm in BM group; P = 0.06) and at day 21 (2.10 ± 0.30 mm in oGVHD group and 2.89 ± 0.32 mm in BM group; P < 0.01). Besides this, we observed reduction in epithelial thickness between the GVHD and BM groups (37.0 ± 6.2 µm and 43.6 ± 3.3 µm respectively; P < 0.05). These data show the usefulness of the electrical impedance method to measure tear osmolarity in mice. We can also conclude that this oGVHD model mimics the tear film alterations found in human dry eye disease, what contributes to give relevance to this model for the study of GVHD.

Sox10 Expression in Goldfish Retina and Optic Nerve Head in Controls and after the Application of Two Different Lesion Paradigms.

The mammalian central nervous system (CNS) is unable to regenerate. In contrast, the CNS of fish, including the visual system, is able to regenerate after damage. Moreover, the fish visual system grows continuously throughout the life of the animal, and it is therefore an excellent model to analyze processes of myelination and re-myelination after an injury. Here we analyze Sox10+ oligodendrocytes in the goldfish retina and optic nerve in controls and after two kinds of injuries: cryolesion of the peripheral growing zone and crushing of the optic nerve. We also analyze changes in a major component of myelin, myelin basic protein (MBP), as a marker for myelinated axons. Our results show that Sox10+ oligodendrocytes are located in the retinal nerve fiber layer and along the whole length of the optic nerve. MBP was found to occupy a similar location, although its loose appearance in the retina differed from the highly organized MBP+ axon bundles in the optic nerve. After optic nerve crushing, the number of Sox10+ cells decreased in the crushed area and in the optic nerve head. Consistent with this, myelination was highly reduced in both areas. In contrast, after cryolesion we did not find changes in the Sox10+ population, although we did detect some MBP- degenerating areas. We show that these modifications in Sox10+ oligodendrocytes are consistent with their role in oligodendrocyte identity, maintenance and survival, and we propose the optic nerve head as an excellent area for research aimed at better understanding of de- and remyelination processes.

CRB2 completes a fully expressed Crumbs complex in the Retinal Pigment Epithelium.

The CRB proteins CRB1, CRB2 and CRB3 are members of the cell polarity complex Crumbs in mammals that together with Scribble and Par complexes stablish the polarity of a variety of cell types. Although many members of the Crumbs complex proteins are expressed in the retinal pigment epithelium (RPE), and even though the mRNA of CRB2 has been detected in ARPE-19 cells and in the RPE/Choroid, to date no CRB protein has yet been found in this tissue. To investigate this possibility, we generated an antibody that specifically recognize the mouse CRB2 protein, and we demonstrate the expression of CRB2 in mouse RPE. Confocal analysis shows that CRB2 is restricted to the apicolateral membrane of RPE cells, and more precisely, in the tight junctions. Our study identified CRB2 as the member of the CRB protein family that is present together with the rest of the components of the Crumbs complex in the RPE apico-lateral cell membrane. Considering that the functions of CRB proteins are decisive in the establishment and maintenance of cell-cell junctions in several epithelial-derived cell types, we believe that these findings are a relevant starting point for unraveling the functions that CRB2 might perform in the RPE.

Postcranial morphology of the middle Pleistocene humans from Sima de los Huesos, Spain.

Current knowledge of the evolution of the postcranial skeleton in the genus Homo is hampered by a geographically and chronologically scattered fossil record. Here we present a complete characterization of the postcranium of the middle Pleistocene paleodeme from the Sima de los Huesos (SH) and its paleobiological implications. The SH hominins show the following: (i) wide bodies, a plesiomorphic character in the genus Homo inherited from their early hominin ancestors; (ii) statures that can be found in modern human middle-latitude populations that first appeared 1.6-1.5 Mya; and (iii) large femoral heads in some individuals, a trait that first appeared during the middle Pleistocene in Africa and Europe. The intrapopulational size variation in SH shows that the level of dimorphism was similar to modern humans (MH), but the SH hominins were less encephalized than Neandertals. SH shares many postcranial anatomical features with Neandertals. Although most of these features appear to be either plesiomorphic retentions or are of uncertain phylogenetic polarity, a few represent Neandertal apomorphies. Nevertheless, the full suite of Neandertal-derived features is not yet present in the SH population. The postcranial evidence is consistent with the hypothesis based on the cranial morphology that the SH hominins are a sister group to the later Neandertals. Comparison of the SH postcranial skeleton to other hominins suggests that the evolution of the postcranium occurred in a mosaic mode, both at a general and at a detailed level.

Human Bone Marrow Stromal Cells Differentiate Into Corneal Tissue and Prevent Ocular Graft-Versus-Host Disease in Mice.

Clinical trials have assessed the use of human bone marrow stromal cells (hBMSCs) for the treatment of immune-related disorders such as graft-versus-host disease (GVHD). In the current study, we show that GFP(+)-transduced hBMSCs generated from bone marrow migrate and differentiate into corneal tissue after subconjunctival injection in mice. Interestingly, these hBMSCs display morphological features of epithelial, stromal, and endothelial cells and appear at different layers and with different morphologies depending on their position within the epithelium. Furthermore, these cells display ultrastructural properties, such as bundles of intermediate filaments, interdigitations, and desmosomes with GFP(-) cells, which confirms their differentiation into corneal tissues. GFP(+)-transduced hBMSCs were injected at different time points into the right eye of lethally irradiated mice undergoing bone marrow transplantation, which developed ocular GVHD (oGVHD). Remarkably, hBMSCs massively migrate to corneal tissues after subconjunctival injection. Both macroscopic and histopathological examination showed minimal or no evidence of GVHD in the right eye, while the left eye, where no hBMSCs were injected, displayed features of GVHD. Thus, in the current study, we confirm that hBMSCs may induce their therapeutic effect at least in part by differentiation and regeneration of damaged tissues in the host. Our results provide experimental evidence that hBMSCs represent a potential cellular therapy to attenuate oGVHD.

Effects of retinoic acid exposure during zebrafish retinogenesis.

Retinoic acid (RA) is an important morphogen involved in retinal development. Perturbations in its levels cause retinal malformations such as microphthalmia. However, the cellular changes in the retina that lead to this phenotype are little known. We have used the zebrafish to analyse the effects of systemic high RA levels on retinogenesis. For this purpose we exposed zebrafish embryos to 0.1µM or 1µM RA from 24 to 48h post-fertilisation (hpf), the period which corresponds to the time of retinal neurogenesis and initial retinal cell differentiation. We did not find severe alterations in 0.1µM RA treated animals, but the exposure to 1µM RA significantly reduced retinal size upon treatment, and this microphthalmia persisted through larval development. We monitored histology and cell death and quantified both the proliferation rate and cell differentiation from 48hpf onwards, focusing on the retina and optic nerve of normal and 1µM treated animals. Retinal lamination and initial neurogenesis are not affected by RA exposure, but we found widespread apoptosis after RA treatment that could be the main cause of microphthalmia. Proliferating cells increased their number at 3days post-fertilisation (dpf) but decreased significantly at 5dpf maintaining the microphthalmic phenotype. Retinal cell differentiation was affected; some cell markers do not reach normal levels at larval stages and some cell types present an increased number compared to those of control animals. We also found the presence of young axons growing ectopically within the retina. Moreover although the optic axons leave the retina and form the optic chiasm they do not reach the optic tectum. The alterations observed in treated animals become more severe as larvae develop.