ABSTRACT
Objective To investigate the isolation and protective effect of a new islet purification solution (IPS)-Optiprep solution on the islet in mouse models. Methods The digested pancreatic islets were divided into the IPS and UW groups according to the islet volume. The pancreatic islets were isolated by the continuous gradient density centrifugation using IPS-Optiprep or UW-Optiprep solutions. The purification efficiency and isolated islet activity of purification solution were compared between two groups. The diabetic mouse models were successfully induced and randomly assigned into three groups. In the experimental group (n=10), the mice received pancreatic islet transplantation using islets isolated and purified by the IPS-Optiprep solution. In the control group (n=10), the mice underwent pancreatic islet transplantation using islets isolated and purified by the UW-Optiprep solution. In the sham surgery group (n=5), the mice merely underwent surgery without pancreatic islet transplantation. Postoperative blood glucose levels were detected and compared among three groups. The blood glucose levels of intraperitoneal glucose tolerance test at postoperative 21 d were statistically compared between the experimental and control groups. The cost of the preparation of two isolation solutions was also compared. Results Compared with the UW group, the islet equivalent (IEQ), islet purity, recovery rate and islet integrity were significantly higher in the IPS group. Islet morphological observation revealed that the islet membrane was complete and the islet diameter in the IPS group was considerably larger than that in the UW group. The activity of purified islets in the UW group was significantly higher than that in the IPS group [(88±5)% vs. (84±3)%, P<0.01]. Compared with the UW-Optiprep solution, identical in vivo islet function was obtained in the IPS-Optiprep solution.The cost of IPS-Optiprep solution was significantly less than that of the UW-Optiprep solution. Conclusions The new IPS-Optiprep solution yields higher islet isolation efficiency, purification, integrity and recovery rate and significantly reduces the purification cost compared with the UW-Optiprep solution. Nevertheless, IPS-Optiprep solution exerts a less protective effect on the activity of islet cells, which is probably correlated with the high islet integrity and the endotoxin in the IPS-Optiprep solution.
ABSTRACT
Con el objeto de conocer el posible efecto del uso y la cobertura del suelo, sobre el perfil de polidispersidadde los ácidos húmicos, se analizaron los horizontes A de tres muestras de suelo de un andisol (Melanudands) del departamento de Caldas, Colombia, con diferentes condiciones de manejo y cobertura: bajo bosque de guadua, bajo café con sombrío de guamo y bajo café de libre exposición. Para ello, en la fracción inferior a 50 µm, se realizó la extracción secuencial de las sustancias húmicas con soluciones de tetraborato (Na2B4O7 0,05 M), pirofosfato (Na4P2O7 0,025 M) e hidróxido de sodio (NaOH 0,1M) y la separación y purificación de los respectivos ácidos húmicos. Para obtener los perfiles se acoplaron las técnicas de separación de cromatografía de exclusión por tamaño utilizando Sephadex G-75 y ultracentrifugación por gradiente de densidad con sacarosa y se elaboraron gráficas de distribución por tamaño (absorbancia (450 nm) vs. volumen eluido). Se encontró que los ácidos húmicos extraídos con hidróxido de sodio presentaron en todas las muestras menor polidispersidad, mayor tamaño, peso y aromaticidad evaluada por la relación E4/E6. Los resultados no mostraron, en general, efecto drástico del uso y la cobertura del suelo, sobre el perfil de polidispersidad y el coeficiente de sedimentación de los ácidos húmicos, lo cual está relacionado con el tamaño, peso y densidad molecular de los mismos. Sin embargo, se encontró que los ácidos húmicos de las muestras de suelo bajo café con sombrío de guamo y café de libre exposición son muy similares entre sí y diferentes de la muestra bajo bosque de guadua, lo que se asoció con un inicio del efecto del uso y la cobertura del suelo sobre el tamaño de los ácidos húmicos del suelo; se presume que a largo término este efecto podría acentuarse y eventualmente ser considerado como indicador de degradación del componente orgánico del suelo.
In order to know the possible effect of the use and the cover of soil, on the polydispersity profile of humic acids were analyzed the A horizon of three samples of an andisol (Melanudand) from the Department of Caldas, Colombia, that have presented different management and coverland as soils under forest of bamboo, coffee with somber of guamo and under free exposition coffee. For this in the lower fraction to 50 µm, the sequential extraction of humic substances was carried out with solutions of sodium tetraborate (Na2B4O7 0.05 M), sodium pyrophosphate (Na4P2O7 0.025 M) and sodium hydroxide (NaOH 0.1M) and the later separation and purification of the respective humic acids. To obtain the polydispersity profiles was applied the exclusion chromatography separation by size technique utilizing Sephadex G-75 and ultracentrifugation by gradient of density with sucrose and they devised graphics of distribution by size (absorbance (450 nm) vs. volume eluted). It was found that the humic acids extracted with sodium hydroxide presented smaller polydispersity, bigger size and molecular weight, as well as, degree of aromatic condensation. The results did not show drastic effect of the use and the coverland , on the polidispersity profile and the coefficient of sedimentation of the humic acids, which is related to the size, weight and molecular density of the same ones. Nevertheless, it was found that the húmic acids of the samples of soil under coffee with somber of guamo and free exposition coffee are very similar among it and different from the sample under forest of bamboo. This fact was associated with a beginning of the effect of the use and the cover of the soil on the size of the humic acids. It presumed that in the long term the effect is accentuated and eventually could be considered as indicator of degradation of the organic component of the soil.