The effect on the electrocatalytic activity of the chemical interaction of selenium with palladium centers: oxygen reduction and methanol oxidation reactions in alkaline medium.

The chemical reactivity of two different selenium precursors (SeO2and Se) with nanoparticulated palladium was studied in a simple aqueous phase synthesis to generate palladium selenides (PdxSey). As confirmed by XRD, XPS, TEM and energy dispersive spectroscopy analyses, the products generated showed different degrees of selenization according to the nature of the chemical precursor. Such degree of selenization was more important with elemental selenium, in contrast to SeO2. Surface electrochemistry and CO stripping in alkaline medium, clearly revealed the different interactions and stability of PdxSeyachieved with the Pd/C precursor depending on the selenium source. The electrocatalysis of the oxygen reduction reaction was also influenced by the Se source, first in the different degree of reactivity, and second in the selectivity of the reduction product between H2O and H2O2, as well as the tolerance to the methanol oxidation reaction.

Synthesis, characterization and biological evaluation of octyltrimethylammonium tetrathiotungstate.

Octyltrimethylammonium tetrathiotungstate salt (ATT-C8) was synthesized and its ability to chelate copper was evaluated. The biological and toxic aspects were evaluated by in vitro and in vivo assays, using bovine aorta endothelial cells (BAEC) and zebrafish (Danio rerio) embryos. The obtained results suggest that ATT-C8 has better biocompatibility, showing a significantly lower lethal concentration 50 (LC50) value in comparison to ammonium tetrathiotungstate (ATT). Zebrafish embryos assay results indicate that both tetrathiotungstate salts at the studied concentrations increase the hatching time. Even more, an in vivo assay showed that synthesized materials behave as copper antagonists and have the ability to inhibit its toxicological effects. Also, both materials were found to be active for the in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The characterization of the materials was carried out using the following spectroscopic techniques: Ultraviolet-Visible (UV-Vis), Fourier Transform Infrared (FTIR) and proton nuclear magnetic resonance (1H-NRM).

Usefulness of serum amylase and lipase as predictors of the severity of post-endoscopic retrograde cholangiopancreatography pancreatitis.

BACKGROUND: Post-ERCP pancreatitis (PEP) is the most common complication of Post-endoscopic retrograde cholangiopancreatography. OBJECTIVE: to demonstrate whether serum amylase and lipase values correlate with the presence and severity of PEP. METHOD: We conducted a retrospective, observational and analytical study of patients who underwent ERCP, those who developed pancreatitis were classified by severity according to the 2012 revised Atlanta criteria and their serum enzyme levels were analyzed. We used ROC (Receiver Operating Characteristics) curves to know the best enzyme cutoff points and analyzed their diagnostic yields. Chi-square, t-distribution and Mann-Whitney U test were used in the variable analysis and it was considered statistically significant when p < 0.05. RESULTS: A total 621 patients, 54 presented pancreatitis. For moderately severe and severe forms: lipase level of 1500 U/L had an area under the curve (AUC) = 0.827, 95% CI (0.67-0.98), sensitivity = 72.7%, specificity = 86%, negative predictive value = 92.5%, p < 0.05. Amylase level of 920 U/L presented AUC = 0.65, 95% CI (0.43-0.86), sensitivity = 63%, specificity = 67%, p > 0.05. CONCLUSIONS: Serum lipase shows correlation with the presence and severity of PEP. Amylase shows no significant correlation with PEP.

ANTECEDENTES: La pancreatitis poscolangiopancreatografía retrógrada endoscópica (PPCPRE) es la complicación más frecuente de este procedimiento. OBJETIVO: Demostrar si la amilasa y la lipasa séricas se correlacionan con la presencia y la gravedad de la PPCPRE. MÉTODO: Realizamos un estudio retrospectivo, observacional y analítico de pacientes a quienes se realizó CPRE. Los que desarrollaron pancreatitis se clasificaron por gravedad de acuerdo con la revisión de Atlanta de 2012 y se analizaron sus concentraciones séricas de enzimas. Empleamos curvas ROC (Receiver Operating Characteristics) para conocer los mejores puntos de corte enzimáticos y analizamos sus rendimientos diagnósticos. Usamos las pruebas de ji al cuadrado, t de Student y U de Mann Whitney para el análisis de las variables, y se consideró estadísticamente significativo un valor de p < 0.05. RESULTADOS: De un total de 621 pacientes, 54 presentaron pancreatitis. Para pancreatitis moderadamente grave y grave, unas cifras de lipasa de 1500 U/l presentaron un área bajo la curva (AUC) = 0.827 (intervalo de confianza del 95% [IC 95%]: 0.67-0.98), con una sensibilidad del 72.7%, una especificidad del 86% y un valor predictivo negativo del 92.5% (p < 0.05); y unas cifras de amilasa de 920 U/l presentaron un AUC = 0.65 (IC 95%: 0.43-0.86), con una sensibilidad del 63% y una especificidad del 67% (p > 0.05). CONCLUSIONES: La lipasa muestra correlación con la presencia y la gravedad de la PPCPRE. La amilasa muestra correlación no significativa con la PPCPRE.

Complicated diverticular colon disease in patients younger than 35 years: report of two cases and literature review.

BACKGROUND: Complicated colonic diverticular disease in young patients is a rare entity, with an incidence <10% from all patients in the largest series. CLINICAL CASES: We present two cases of complicated diverticular disease in patients <35 years old treated at the Hospital Juárez of México City. Both patients had acute abdominal pain with several days of evolution. In both patients, emergency surgery was performed and postoperative evolution was favorable. CONCLUSIONS: Some authors have concluded that diverticulitis in younger patients demonstrates a more aggressive course than in older patients and with an increased risk of complications. Therefore, most physicians recommended elective resection after a single attack in such patients. Conversely, some recent reports highlighted that the clinical course and complications are similar in both age groups.

Enfermedad diverticular del colón complicada en pacientes menores de 35 años: presentación de dos casos y revisión de la literatura / Complicated diverticular colon disease in patients younger than 35 years: report of two cases and literature review

Introducción: La enfermedad diverticular complicada del colon es rara en pacientes jóvenes, estimándose una incidencia menor a 10 % en las grandes series. Casos clínicos: Se describen dos pacientes menores de 35 años de edad con complicaciones de enfermedad diverticular, atendidos en el Hospital Juárez de México; ambos presentaron cuadro de abdomen agudo de pocos días de evolución y requirieron cirugía de urgencia, con buena evolución posoperatoria. Conclusiones: Algunos autores consideran que la diverticulitis en los pacientes jóvenes puede tener un comportamiento con más complicaciones que en lo mayores. Incluso se recomienda la resección electiva del segmento afectado después del primer episodio de diverticulitis. No obstante, informes recientes han señalado que el comportamiento de las complicaciones de la enfermedad diverticular puede ser el mismo en los pacientes jóvenes y en los de mayor edad.

BACKGROUND: Complicated colonic diverticular disease in young patients is a rare entity, with an incidence <10% from all patients in the largest series. CLINICAL CASES: We present two cases of complicated diverticular disease in patients <35 years old treated at the Hospital Juárez of México City. Both patients had acute abdominal pain with several days of evolution. In both patients, emergency surgery was performed and postoperative evolution was favorable. CONCLUSIONS: Some authors have concluded that diverticulitis in younger patients demonstrates a more aggressive course than in older patients and with an increased risk of complications. Therefore, most physicians recommended elective resection after a single attack in such patients. Conversely, some recent reports highlighted that the clinical course and complications are similar in both age groups.

[Postobstetric rectovaginal fistula: surgical treatment using endorectal advancement flap]. / Fístula rectovaginal posobstétrica: tratamiento quirúrgico mediante avance de colgajo endorrectal.

BACKGROUND: Rectovaginal fistulas account for <5% of all rectal fistulas. Obstetrical injuries are the most common cause of these types of fistulas. There have been a multitude of surgical approaches developed for operative repair. METHODS: Between January 1992 and December 2006, 16 patients with postobstetric rectovaginal fistula were treated at the Hospital Juárez of México. Age, type of obstetric trauma, time elapsed between delivery and beginning of symptoms, location, and size of the fistulas, rate of success and recurrence with the use of endorectal flap, and need for complementary sphincteroplasty were all evaluated. RESULTS: Median age of the patients was 25.6 years. All women reported that their symptoms began after a vaginal delivery that included an episiotomy or 4th degree laceration. All fistulas were low and small (<2.5 cm in diameter). Patients received bowel preparation and underwent rectovaginal repair using endorectal advancement flap. In two cases, additional overlap repair of the anal sphincter was performed. Result of repair was good to excellent in 15 patients (93.7%). There were no operative mortalities, and no covering stomas were used. CONCLUSIONS: Endorectal flap repair provides successful postobstetric rectovaginal fistula closure. Concomitant sphincteroplasty may be necessary in some cases.

Fístula rectovaginal posobstétrica: tratamiento quirúrgico mediante avance de colgajo endorrectal / Postobstetric rectovaginal fistula: surgical treatment using endorectal advancement flap

Introducción: Las fístulas rectovaginales ocurren con una frecuencia menor a 5 % respecto a otros tipos de fístulas de la región anorrectal; el trauma obstétrico es la causa más común de este tipo de fístulas. Existen diversos procedimientos quirúrgicos para la reparación de las mismas. Material y métodos: Se realizó un estudio de 16 pacientes con diagnóstico de fístula rectovaginal posobtétrica, atendidas en el Hospital Juárez de México entre enero de 1992 y diciembre de 2006. Se analizó edad de las pacientes, tipo de trauma obstétrico, tiempo de inicio de la sintomatología después del parto, localización y tamaño de la fístula, índice de éxito y recidivas mediante el tratamiento con avance de colgajo endorrectal, y necesidad de esfinteroplastia complementaria. Resultados: La edad promedio fue de 25.6 años. En todas las pacientes, la sintomatología inició después de un parto vaginal durante el cual se realizó episiotomía o hubo desgarro perineal. Todas las fístulas fueron menores de 2.5 cm de diámetro y de localización baja. Con el colon preparado, en todas las pacientes se reparó la fístula rectovaginal mediante avance de colgajo endorrectal. En dos pacientes se llevó acabo, además, esfinteroplastia del esfínter anal. Los resultados fueron satisfactorios en 15 pacientes (93.7 %); no hubo mortalidad operatoria y no fueron utilizados estomas de protección. Conclusiones: El colgajo endorrectal es un procedimiento seguro para la reparación de fístulas rectovaginales de origen posobstétrico, algunos casos pueden requerir esfinteroplastia del esfínter anal.

BACKGROUND: Rectovaginal fistulas account for <5% of all rectal fistulas. Obstetrical injuries are the most common cause of these types of fistulas. There have been a multitude of surgical approaches developed for operative repair. METHODS: Between January 1992 and December 2006, 16 patients with postobstetric rectovaginal fistula were treated at the Hospital Juárez of México. Age, type of obstetric trauma, time elapsed between delivery and beginning of symptoms, location, and size of the fistulas, rate of success and recurrence with the use of endorectal flap, and need for complementary sphincteroplasty were all evaluated. RESULTS: Median age of the patients was 25.6 years. All women reported that their symptoms began after a vaginal delivery that included an episiotomy or 4th degree laceration. All fistulas were low and small (<2.5 cm in diameter). Patients received bowel preparation and underwent rectovaginal repair using endorectal advancement flap. In two cases, additional overlap repair of the anal sphincter was performed. Result of repair was good to excellent in 15 patients (93.7%). There were no operative mortalities, and no covering stomas were used. CONCLUSIONS: Endorectal flap repair provides successful postobstetric rectovaginal fistula closure. Concomitant sphincteroplasty may be necessary in some cases.