Use of Chitosan from Southern King Crab to Develop Films Functionalized with RGD Peptides for Potential Tissue Engineering Applications.

Southern King Crab (SKC) represents an important fishery resource that has the potential to be a natural source of chitosan (CS) production. In tissue engineering, CS is very useful to generate biomaterials. However, CS has a lack of signaling molecules that facilitate cell-substrate interaction. Therefore, RGD (arginine-glycine-aspartic acid) peptides corresponding to the main integrin recognition site in extracellular matrix proteins have been used to improve the CS surface. The aim of this study was to evaluate in vitro cell adhesion and proliferation of CS films synthesized from SKC shell wastes functionalized with RGD peptides. The FTIR spectrum of CS isolated from SKC shells (SKC-CS) was comparable to commercial CS. Thermal properties of films showed similar endothermic peaks at 53.4 and 53.0 °C in commercial CS and SKC-CS, respectively. The purification and molecular masses of the synthesized RGD peptides were confirmed using HPLC and ESI-MS mass spectrometry, respectively. Mouse embryonic fibroblast cells showed higher adhesion on SKC-CS (1% w/v) film when it was functionalized with linear RGD peptides. In contrast, a cyclic RGD peptide showed similar adhesion to control peptide (RDG), but the highest cell proliferation was after 48 h of culture. This study shows that functionalization of SKC-CS films with linear or cyclic RGD peptides are useful to improve effects on cell adhesion or cell proliferation. Furthermore, our work contributes to knowledge of a new source of CS to synthesize constructs for tissue engineering applications.

Effects of elderflower extract enriched with polyphenols on antioxidant defense of salmon leukocytes

BACKGROUND: In fish farming, the plant extracts containing antioxidant compounds have been added to the diet for enhancing pathogen resistance. In vitro studies evaluating the antioxidant effect of herbal extracts on fish cell models have focused on ROS production and the respiratory burst mechanism. However, the effects on enzymatic antioxidant defense on salmon leukocytes have not been evaluated. This study aims to evaluate the enzymatic antioxidant defense and ROS-induced cell damage in Salmon Head Kidney-1 (SHK-1) cell line exposed to polyphenol-enriched extract from Sambucus nigra flowers. RESULTS: Firstly, the Total Reactive Antioxidant Power (TRAP) assay of elderflower polyphenol (EP) was evaluated, showing 459 and 489 times more active than gallic acid and butyl hydroxy toluene (BHT), respectively. The toxic effect of EP on salmon cells was not significant at concentrations below 120 mg/ mL and no hemolysis activity was observed between 20 and 400 mg/mL. The treatment of SHK-1 cell line with EP decreased both the lipid peroxidation and protein oxidation induced by H2O2, which could be associated with decreasing oxidative stress in the SHK-1 cells since the GSH/GSSG ratio increased when only EP was added. CONCLUSIONS: These results suggest that plant extracts enriched with polyphenols could improve the enzymatic antioxidant defense of salmon leukocytes and protect the cells against ROS-induced cell damage

Development of Useful Biomaterial for Bone Tissue Engineering by Incorporating Nano-Copper-Zinc Alloy (nCuZn) in Chitosan/Gelatin/Nano-Hydroxyapatite (Ch/G/nHAp) Scaffold.

Ceramic and metallic nanoparticles can improve the mechanical and biological properties of polymeric scaffolds for bone tissue engineering (BTE). In this work, nanohydroxyapatite (nHAp) and nano-copper-zinc alloy (nCuZn) were added to a chitosan/gelatin (Ch/G) scaffold in order to investigate the effects on morphological, physical, and biocompatibility properties. Scaffolds were fabricated by a freeze-drying technique using different pre-freezing temperatures. Microstructure and morphology were studied by scanning electron microscopy (SEM), glass transition (Tg) was studied using differential scanning calorimetry (DSC), cell growth was estimated by MTT assay, and biocompatibility was examined in vitro and in vivo by histochemistry analyses. Scaffolds and nanocomposite scaffolds presented interconnected pores, high porosity, and pore size appropriate for BTE. Tg of Ch/G scaffolds was diminished by nanoparticle inclusion. Mouse embryonic fibroblasts (MEFs) cells loaded in the Ch/G/nHAp/nCuZn nanocomposite scaffold showed suitable behavior, based on cell adhesion, cell growth, alkaline phosphatase (ALP) activity as a marker of osteogenic differentiation, and histological in vitro cross sections. In vivo subcutaneous implant showed granulation tissue formation and new tissue infiltration into the scaffold. The favorable microstructure, coupled with the ability to integrate nanoparticles into the scaffold by freeze-drying technique and the biocompatibility, indicates the potential of this new material for applications in BTE.

Incidencia de falla anastomótica en intestino delgado, colon y recto, Bogotá, Colombia / Incidence of anastomotic failure in small bowel, colon and rectum, Bogotá, Colombia

Introducción. La falla anastomótica es una de las principales complicaciones de las cirugías gastrointestinales, que se presenta en 3,4 a 15 % de los pacientes, aproximadamente. En Colombia, no se conoce con exactitud la incidencia de falla anastomótica. Objetivo. Determinar la incidencia de falla anastomótica en cirugías intestinales en dos hospitales de IV nivel de Bogotá. Métodos. Se llevó a cabo un estudio prospectivo de cohorte que incluyó pacientes sometidos a anastamosis y a quienes se les hizo seguimiento hasta de 30 días. Se realizó un análisis descriptivo de la información, asociaciones entre variables mediante la prueba de ji al cuadrado y, además, se emplearon gráficas de KaplanMeier para determinar el tiempo hasta el evento. Los datos se analizaron en Stata 13®. Resultados. Se incluyeron 195 pacientes. El 47,1 % era de sexo masculino y la mediana de la edad fue de 60 años (rango intercuartílico, RIC: 48 a 70). La incidencia de falla anastomótica fue de 10,8 % y la tasa de incidencia fue de 10,2 por 1.000 personas/año. El 29,7 % de los pacientes presentaron complicaciones posoperatorias y se presentó una mortalidad de 9,7 %. La mediana de la estancia hospitalaria fue de 8 días (RIC: 5 a 16). Conclusiones. La incidencia de fístula de la anastomosis que se presentó estuvo acorde con lo reportado en la literatura científica a nivel mundial. El antecedente de cirugía abdominal así como la cirugía de urgencia fueron los factores frecuentes entre los pacientes que presentaron falla anastomótica

Introduction: Anastomotic leak is one of the main complications of patients submitted to gastrointestinal surgery. It occurs in approximately in 3.4% to 15% of cases. In Colombia the overall incidence of anastomotic leak is not known. Material and methods: A prospective cohort study that included patients undergoing anastamosis and who were followed up for up to 30 days. A descriptive analysis of the information was performed. The variables were analyzed with the chi-square test and the Kaplan-Meller graphs were used to determine the time to the event. Data analyses was performed on STATA 13. Results: 195 patients were admitted. 47.1% were male, and the median age of the study group was 60 years (ICR: 48-70). The incidence of anastomotic failure was 10.8% and the incidence rate was 10.2 per 1000 person-years; 29.7% of the patients presented postoperative complications and a mortality rate of 9.7%. The median hospital stay was 8 days (ICR: 5 - 16). Conclusion: The incidence of anastomotic leak observed appears in accordance with reports published in the world literature. The history of abdominal surgery as well as emergency surgery were the most frequent factors among the patients who developed anastomosis leak

Cirugía de abdomen abierto en gineco obstetricia: indicaciones, técnica y manejo / Indications, technique and management of open abdominal surgery in obstetrics and gynaecology

La cirugía de abdomen abierto para el manejo de algunas patologías severas en obstetricia ha aumentado y actualmente es común en muchas de nuestras pacientes. Los beneficios incluyen la prevención y tratamiento del Síndrome de Hipertensión Abdominal (HIA), de las infecciones de la cavidad peritoneal y el del Síndrome Compartimental Abdominal (SCA) secundario a enfermedades potencialmente catastróficas como la preeclampsia severa y Síndrome de HELLP. La presente revisión explora los mecanismos de infección, las consecuencias fisio-patológicas del SCA y las nuevas técnicas quirúrgicas de la cirugía de abdomen abierto para el manejo adecuado de estas entidades.

Estudio clínico controlado de un esquema de 4 meses en el tratamiento acortado de la tuberculosis pleural / A controlled clinical trial of 4 months regimens in the shortened treatment of tuberculous pleural efusion

La tuberculosis pleural recibe el mismo tratamiento que cualquier otro tipo de tuberculosis, sin embargo se ha demostrado que la población bacilar es menor en esta presentación, y su fisiopatología es diferente dado que el comportamiento es de una tuberculosis primaria con gran compromiso inflamatorio dependiente de linfocitos CD4 en el espacio pleural. Por lo tanto el racionalizar un tratamiento con base en los conocimientos fisiológicos con el fín de disminuir los costos y los efectos adversos es el objetivo. Se ingresaron al protocolo de investigación un total de 50 pacientes; 31 con esquema a 4 meses y 19 con esquema a 6 meses como grupo control. El esquema que se utilizó fue Isoniacida 300 mg, Rifampicina 600 mg, Pirazinamida 1500 mg, Estreptomicina 1 gr diariamente por 4 semanas, continuando con Isoniacida 900 mg, Rifampicina 600 mg bisemanal por 4 meses, y el grupo control con esquema tradicional acortado supervisado a 6 meses. No hubo diferencia significativa en los grupos de edad, efectos adversos, abandono de tratamiento ni recaidas con un seguimiento a los 18 meses (promedio). El diagnóstico de TBC pleural se obtuvo en todos los pacientes, mediante biopsia pleural. Se concluye que la terapéutica con cuatro drogas a cuatro meses es efectiva para la TBC pleural en pacientes con baja población bacilar (baciloscopia de esputo negativa).