Rectopexia laparoscópica con técnica de Orr-Loygue para el tratamiento del prolapso rectal / Laparoscopic Orr-Loygue rectopexy with mesh for the treatment of rectal prolapse

Introducción: Existen múltiples alternativas para el tratamiento quirúrgico del prolapso rectal mediante procedimientos de fijación, resección o combinados. Si bien el abordaje perineal evita el acceso a la cavidad peritoneal, se acompaña de una tasa de recidiva mayor en relación al abordaje abdominal. Descripción: Se presenta una paciente de 66 años, histerectomizada por vía laparotómica, con un prolapso rectal externo y reductible de 1 año de evolución, sin incontinencia fecal ni constipación. La endoscopia preoperatoria descartó patología colónica asociada. Abordaje laparoscópico en posición de Trendelenburg lateralizado a la derecha. Como es habitual en estos casos se observa la presencia de dolicosigma y fondo de saco de Douglas profundo y se evidencia también la cicatriz de la cesárea. El procedimiento comienza con la apertura peritoneal a nivel del promontorio y la movilización de la unión rectosigmoidea, identificando el uréter izquierdo. Se continua la disección circunferencial tras la apertura de la reflexión peritoneal hasta la altura de la cúpula vaginal. La rectopexia se realiza según la técnica de Orr-Loygue mediante la fijación de la malla por una parte a ambas caras laterales del recto y por otra al promontorio sacro con puntos de polipropileno 2-0, cuidando de no lesionar los vasos ilíacos y los uréteres. Finalmente se cierra la reflexión peritoneal con poliglactina para aislar las mallas protésicas del contenido visceral. La paciente tuvo una buena evolución postoperatoria, otorgándose el alta a las 48 h. Tras 8 meses de seguimiento se encuentra asintomática, con tránsito digestivo y continencia fecal sin alteraciones. Conclusión: El abordaje laparoscópico para el tratamiento del prolapso rectal es seguro y ofrece las ventajas de la cirugía mini-invasiva. La rectopexia con malla protésica es un procedimiento técnicamente desafiante, aunque con mejores resultados alejados. (AU)

Introduction: There are multiple alternatives for the surgical treatment of rectal prolapse through fixation, resection or combined procedures. Although the perineal approach avoids access to the peritoneal cavity, it is associated with a higher recurrence rate than the abdominal approach. Description: The video shows a 66-year-old female patient, hysterectomized by laparotomy, with a 1-year history of reduciblefull-thickness rectal prolapse, without fecal incontinence or constipation. Preoperative endoscopy ruled out associated colonic pathology. The laparoscopic approach is done with the patient placed in Trendelenburg and tilted to the right. As usual in these cases, the presence of dolichosigma and deep Douglas pouch is observed, as well as the cesarean section scar. The procedure begins with the peritoneal opening at the level of the promontory and the mobilization of the rectosigmoid junction, identifying the left ureter. Circumferential dissection is continued after opening the peritoneal reflection up to the level of the vaginal vault. Rectopexy is performed according to the Orr-Loygue technique by fixing the mesh to both lateral aspects of the rectum on one side and to the sacral promontory on the other side with 2-0 polypropylene interrupted sutures, taking care not to injure the iliac vessels and ureters. Finally, the peritoneum is closed with a running suture with polyglactin to isolate the prosthetic mesh from the visceral content. The patient had a good postoperative outcome and was discharged at 48 h. After 8 months of follow-up, she is asymptomatic and has normal colonic transit and fecal continence. Conclusion: the laparoscopic approach for the treatment of rectal prolapse is safe and offers the advantages of minimally invasive surgery. Prosthetic mesh rectopexy is a technically challenging procedure, although has better distant results. (AU)

One-Pot Graphene Supported Pt3Cu Nanoparticles-From Theory towards an Effective Molecular Oxygen Reduction Reaction Catalyst.

In this work, recent research progresses in the formation of Pt3Cu nanoparticles onto the surface of graphene are described, and the obtained results are contrasted with previously published theoretical studies. To form these nanoparticles, tetrabutylammonium hexachloroplatinate, and copper acetylacetonate are used as platinum and copper precursors, respectively. Oleylamine is used as a reductor and a solvent. The obtained catalyst is characterized via X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive spectroscopy X-ray (EDS). To assess the catalytic activity, the graphene-supported Pt3Cu material is tested with cyclic voltammetry, "CO stripping", and oxygen reduction reaction potentiodynamic curves to find the nature and the intrinsic electrochemical activity of the material. It can be observed that the tetrabutylammonium cation plays a critical role in anchoring and supporting nanoparticles over graphene, from which a broad discussion about the true nature of the anchoring mechanism was derived. The growth mechanism of the nanoparticles on the surface of graphene was observed, supporting the conducted theoretical models. With this study, a reliable, versatile, and efficient synthesis of nanocatalysts is presented, demonstrating the potentiality of Pt3Cu/graphene as an effective cathode catalyst. This study demonstrates the importance of reliable ab inito theoretical results as a useful source of information for the synthesis of the Pt3Cu alloy system.

MnO2-Ir Nanowires: Combining Ultrasmall Nanoparticle Sizes, O-Vacancies, and Low Noble-Metal Loading with Improved Activities towards the Oxygen Reduction Reaction.

Although clean energy generation utilizing the Oxygen Reduction Reaction (ORR) can be considered a promising strategy, this approach remains challenging by the dependence on high loadings of noble metals, mainly Platinum (Pt). Therefore, efforts have been directed to develop new and efficient electrocatalysts that could decrease the Pt content (e.g., by nanotechnology tools or alloying) or replace them completely in these systems. The present investigation shows that high catalytic activity can be reached towards the ORR by employing 1.8 ± 0.7 nm Ir nanoparticles (NPs) deposited onto MnO2 nanowires surface under low Ir loadings (1.2 wt.%). Interestingly, we observed that the MnO2-Ir nanohybrid presented high catalytic activity for the ORR close to commercial Pt/C (20.0 wt.% of Pt), indicating that it could obtain efficient performance using a simple synthetic procedure. The MnO2-Ir electrocatalyst also showed improved stability relative to commercial Pt/C, in which only a slight activity loss was observed after 50 reaction cycles. Considering our findings, the superior performance delivered by the MnO2-Ir nanohybrid may be related to (i) the significant concentration of reduced Mn3+ species, leading to increased concentration of oxygen vacancies at its surface; (ii) the presence of strong metal-support interactions (SMSI), in which the electronic effect between MnOx and Ir may enhance the ORR process; and (iii) the unique structure comprised by Ir ultrasmall sizes at the nanowire surface that enable the exposure of high energy surface/facets, high surface-to-volume ratios, and their uniform dispersion.

Total skin electron beam therapy for primary cutaneous T-cell lymphomas: clinical characteristics and outcomes in a Mexican reference center.

AIM: The aim of this study was to assess treatment modalities, treatment response, toxicity profile, disease progression and outcomes in 14 patients with a confirmed diagnosis of primary cutaneous T-cell lymphoma (PCTCL) treated with total skin electron beam therapy (TSEBT). BACKGROUND: Primary cutaneous lymphomas (PCLs) are extranodal non-Hodgkin lymphomas originating in the skin without evidence of extracutaneous disease at diagnosis. Despite advances in systemic and local therapy options, the management of advanced stages remains mostly palliative. MATERIALS AND METHODS: This is a retrospective study of patients with PCTCL, diagnosed and treated in a reference center in Mexico City, analyzing treatment modalities, response to treatment, long-term outcome, and mortality. RESULTS: Eight males (57%) and 6 (43%) females were identified. Most patients were stage IVA (n = 5, 36%) followed by stage IB and IIB (28.5% and 21.4%, respectively). Eleven patients received the low-dose RT scheme (12 Gy), 1 patient, the intermediate-dose RT scheme (24 Gy), and 2 patients, the conventional-dose RT scheme (36 Gy). Mean follow-up time was 4.6 years. At first follow-up examination, 6-8 weeks after radiotherapy, the overall response rate (ORR) for the cohort was 85%. The median PFS for the whole cohort was 6 months. CONCLUSION: This study reinforces the role of TSEBT when compared with other treatment modalities and novel agents. Low-dose TSEBT is now widely used because of the opportunity for retreatment.

Revisiting direct electron transfer in nanostructured carbon laccase oxygen cathodes.

The biocatalytic electroreduction of oxygen has been studied on large surface area graphite and Vulcan® carbon electrodes with adsorbed Trametes trogii laccase. The electrokinetics of the O2 reduction reaction (ORR) was studied at different electrode potentials, O2 partial pressures and concentrations of hydrogen peroxide. Even though the overpotential at 0.25 mA·cm(-2) for the ORR at T1Cu of the adsorbed laccase on carbon is 0.8 V lower than for Pt of similar geometric area, the rate of the reaction and thus the operative current density is limited by the enzyme reaction rate at the T2/T3 cluster site for the adsorbed enzyme. The transition potential for the rate determining step from the direct electron transfer (DET) to the enzyme reaction shifts to higher potentials at higher oxygen partial pressure. Hydrogen peroxide produced by the ORR on bare carbon support participates in an inhibition mechanism, with uncompetitive predominance at high H2O2 concentration, non-competitive contribution can be detected at low inhibitor concentration.

Cura de ORR en pie diabético / Cure for ORR in the diabetic foot

El principio dominante del método de Orr es favorecer con la inmovilización rigurosa la defensa tisular contra la infección. Durante la Guerra Civil Española era utilizado en fracturas abiertas, se realizaba limpieza quirúrgica, se aplicaba vaselina sobre la herida y se cubría con bota de yeso por 2 o 3 semanas, a menos que el paciente presentara fiebre. Evaluar la efectividad del uso de la "cura de Orr" en pie diabético en el Hospital Universitario de Coro "Dr. Alfredo Van Grieken", durante el período octubre 2008-marzo 2009. Estudio prospectivo, descriptivo en un lapso de 6 meses, incluyendo pacientes con pie diabético grado III y IV según la clasificación de Wagner modificada. Se evalúa número de curas de Orr necesarias para la cicatrización de la úlcera, intervalo de tiempo del cambio de la cura, período de cicatrización de las lesiones y complicaciones presentadas con este método de cura. A un total de siete pacientes durante el período octubre 2008-marzo 2009, se les realizó entre 4 y 7 curas para lograr cicatrización, la cual se obtuvo antes de los 06 meses en 100 por ciento de los pacientes, realizándose el cambio de cura en intervalos de tiempo variables, presentando un paciente atopia dermatológica al material utilizado. La técnica de Orr es una buena opción para el manejo de úlcera por pie diabético, con resultados sarisfactorios, obteniéndose un pie funcional.