[Surgical suspensions, a quality factor in pediatric surgical patient care]. / Suspensiones quirúrgicas, un factor de calidad en la asistencia al paciente quirúrgico pediátrico.

OBJECTIVE: To identify the factors that influence surgical suspensions (SQ) in a pediatric surgery service, to estimate its economic impact and to analyze the effect that strategies aimed at increasing efficiency and improving medical-surgical care would have. MATERIALS AND METHODS: Retrospective analysis of SQ in 2015, depending on the patient, organization or professionals, time of year, schedule (morning or afternoon) and type of surgery: major ambulatory surgery (CMA) or with hospital admission. Implementation of corrective measures against the main causes and subsequent comparative analysis in 2016 and 2017, comparing the results using Chi2 and Fisher's test. Evaluation of the economic impact based on lost operating hours. RESULTS: The SQ rate in 2015 was 8.9%: 90.7% attributable to the patient, 6.8% to organizational factors and 2.7% to professionals. There were no significant differences according to the time of year or between morning or afternoon, but they were significantly more frequent in CMA (10.84% vs. 2.63%, p <0.001). After introducing improvement measures, SQ decreased significantly in 2016 and 2017 (6.2 and 4.9% respectively, p<0.01), mainly patient-dependent (80 and 73.9%, respectively, p=0.03). There were no differences between CMA and surgeries with admission and there was a decrease in the associated costs (€ 40,946 in 2015, € 18,217 in 2017). CONCLUSIONS: SQ represent an inconvenience for the patient, professionals and institution, that can be minimized with the implantation of simple, feasible and contrasted measures, that increase the efficiency and, probably, the satisfaction of users and professionals.

OBJETIVOS: Identificar los factores que influyen en las suspensiones quirúrgicas (SQ) en un servicio de cirugía pediátrica, estimar su impacto económico y analizar el efecto que tendrían estrategias dirigidas a incrementar la eficiencia y mejorar la atención médico-quirúrgica. MATERIAL Y METODOS: Análisis retrospectivo de las SQ en 2015, según dependieran del paciente, la organización o los profesionales, la época del año, el horario (mañana o tarde) y el tipo de cirugía: régimen de cirugía mayor ambulatoria (CMA) o con ingreso hospitalario. Implantación de medidas correctoras frente a las principales causas y análisis comparativo posterior en los años 2016 y 2017, comparando los resultados mediante Chi2 y test de Fisher. Valoración del impacto económico en base a horas de quirófano perdidas. RESULTADOS: La tasa de SQ en 2015 fue del 8,9%: 90,7% atribuibles al paciente, 6,8% a factores organizativos y 2,7% a profesionales. No hubo diferencias significativas según la época del año ni entre mañana o tarde, pero sí fueron significativamente más frecuentes en CMA (10,84% vs. 2,63%; p<0,001). Tras introducir medidas de mejora las SQ disminuyeron significativamente en 2016 y 2017 (6,2 y 4,9% respectivamente, p<0,01), fundamentalmente las dependientes de paciente (80 y 73,9%, respectivamente, p=0,03). No hubo diferencias entre CMA y cirugías con ingreso y se produjo una disminución de los costes asociados (40.946 € en 2015, 18.217 € en 2017). CONCLUSIONES: Las SQ suponen inconvenientes para el paciente, los profesionales y la institución, que pueden ser minimizados con la implantación de medidas sencillas, factibles y contrastadas, que aumenten la eficiencia y, probablemente, la satisfacción de usuarios y profesionales.

Impacto del estrés oxidativo sobre las lesiones cutáneas causadas por radiaciones ionizantes / Impact of the oxidative stress on cutaneous lesions caused by ionizing radiations

Los efectos inducidos por exposición de manera accidental o terapéutica a dosis de radiaciones ionizantes inducen varios eventos celulares que afectan el proceso de cicatrización de la piel, y tiene gran impacto en la prognosis y supervivencia de individuos afectados. La información existente sobre los efectos nocivos por altas exposiciones a radiaciones proviene a partir de los accidentes ocurridos por las bombas atómicas en Hiroshima y Nagasaki produciendo problemas de salud por leucemias y linfomas en los sobrevivientes. El síndrome de radiación aguda (SRA) generalmente inicia durante las dos horas inmediatas posteriores a la exposición, y la severidad de las lesiones depende de la dosis y del tiempo de exposición. El desarrollo de las lesiones por el daño como efectos tardíos a exposiciones por radiaciones es más complejo y determina no únicamente el daño al parénquima celular sino también se presentan daños en el tejido vascular y en otros tejidos de soporte. Al menos parcialmente estos eventos se presentan a consecuencia del estrés oxidativo generado por el excesivo incremento de especies reactivas del oxígeno (EROs). Se han estado estudiando componentes comerciales como blancos potenciales para la prevención de los daños causados por radiaciones en piel que tienen una amplia actividad contra múltiples citocinas involucradas en los procesos de la lesión cutánea y por otro lado se están estudiando fármacos que reaccionan con los radicales libres o indirectamente inhiben la expresión de las enzimas que generan la producción de EROs o bien aumentan la expresión de enzimas antioxidantes intracelulares

A novel type of cell-cell cooperation between epithelial cells.

Ma104 cells (renal, epithelial) have a peculiar way of resisting ouabain: their Na+,K(+)-pumps bind the drug with high affinity, cellular K+ is lost and cell division arrested, but cells do not detach as most cell types do. Then, if up to 4 days later the drug is removed, Ma104 cells recover K+ and resume proliferation (Contreras et al., 1994). In the present work, we investigate whether Ma104 cells are able to protect ouabain-sensitive MDCK cells in co-culture. The main finding is that they do, but in this case protection is not elicited by the usual mechanism of maintaining the K+ content of neighboring cells through cell-cell communications. Ma104 cells treated with ouabain simply remain attached to the substrate and to their MDCK neighbors, and both cells lose K+. This attachment includes tight junctions, because the transepithelial electrical resistance of the monolayers is not abolished by ouabain. Although the beta-subunit of the Na+,K(+)-ATPase is known to possess molecular characteristics of cell-cell attachment molecules, attachment between Ma104-MDCK cells does not seem to be mediated by this enzyme, as immunofluorescence analysis reveals that Na+,K(+)-ATPase is only inserted in the plasma membrane facing a neighboring cell of the same type.

Expression of potassium channels in epithelial cells depends on calcium-activated cell-cell contacts.

Harvesting MDCK cells with trypsin-EDTA reduces potassium currents (IK) to a mere 10%, presumably by hydrolysis of K+ channels, but replating at confluence restores them in 12-18 hr, through a process that requires transcription, translation and exocytic fusion of intracellular membrane vesicles to the plasma membrane (Ponce & Cereijido, 1991; Ponce et al., 1991a). In the present work we find that this restoration of IK also requires cell-cell contacts and the presence of 1.8 mM Ca2+. The role of extracellular Ca2+ may be substituted by 2.0 microM TRH, 10 nM PMA or 200 micrograms/ml DiC8. drugs that stimulate the system of phospholipase C (PLC) and protein kinase C (PKC). Conversely, the recovery of IK triggered by Ca-dependent contacts can be blocked by 110 microM neomycin, 2.0 microM H7, and 250 nM staurosporine, inhibitors of PLC and PKC. These results suggest that the expression of new K+ channels depends on Ca(2+)-activated contacts with neighboring cells and that the information is conveyed through PLC and PKC, a process in keeping with changes in its enzymatic activity and cellular distribution of PKC. Plasma membrane is also reduced and restored upon harvesting and replating, and depends on Ca(2+)-activated contracts. However, the effects of the chemicals tested on IK differ from the ones they elicit on the recovery of plasma membrane, suggesting that cells can independently regulate their population of K+ channels and the surface of their membrane.

Human somatotropin binding to rabbit kidney microsomal fraction.

Specific binding of 125I-labelled human somatotropin was demonstrated in microsomal membranes (microsomes) from rat and rabbit kidneys. Female rabbit kidney microsomes showed the highest binding activity and were used for further study. The association of 125I-labelled human somatotropin was time- and temperature-dependent and the binding reaction was reversible. Scatchard analysis of saturation data indicated a dissociation equilibrium constant, KD, of 56 pM and a binding capacity of 37 fmol per mg of protein. Similar results were obtained from competition experiments. Binding of 125I-labelled human somatotropin to the microsomes was specifically inhibited by hormones with lactogenic activity. The binding sites, as well as 125I-labelled human somatotropin, were not inactivated on incubation. Treatment of the microsomes with trypsin and chymotrypsin decreased the specific binding by over 90%. Preheating of the microsomes at 55 degrees C for 15 min abolished 50% of the specific binding activity.

Characterization of human somatotropin binding to detergent-solubilized lactogenic receptors from rat liver.

Lactogenic receptors from rat liver microsomal fraction ('microsomes') were extracted by treatment with 1% (w/v) Triton X-100. Triton X-100 exerts an inhibitory effect on both the binding reaction and the separation of the free hormone from the complex. The association and dissociation of 125I-labelled human somatotropin are time- and temperature-dependent processes. The association rate constant, k1, is 6.7 x 10(6) mol . litre-1 . min-1 at 25 decrees C, and the dissociation rate constant, k-1, is 1.1 x 10(-3) min-1 at 25 degrees C. Scatchard analysis of saturation data reveals the existence of a single class of receptors and that solubilization leads to a slight decrease in affinity and a sharp increase in binding capacity. The dissociation constant, Kd, of the solubilized preparation is 0.22 nM and the binding capacity 2900 fmol/mg of protein. Similar results were obtained from competition experiments. Binding of 125I-labelled human somatotropin to the solubilized receptors is specifically inhibited by hormones with lactogenic activity. Incubation of the solubilized preparation with trypsin resulted in an 80% decrease in binding activity. The solubilized form of the receptor has a slightly increased sensitivity to the inactivation by trypsin, heat and extremes of pH, with respect to the membrane-bound form.