Experimental study of a modified extraction method of mouse islets / 器官移植

Objective To investigate the improvement and effect of the method of islet extraction in mice. Methods According to different islet extraction methods, all mice were randomly divided into the common bile duct puncture group (n=100) and common bile duct puncture combined with in situ pancreatic injection group (combined injection group, n=100). Common bile duct puncture combined with in situ pancreatic injection was utilized as the modified method. The islets were selected and purified under stereomicroscope. The morphology and purification of islets were identified. The islet yield and success rate of islet extraction were statistically compared between two groups. The survival of islets after 1 week culture in vitro was analyzed, and the insulin secretion function of islets after 24 h and 4 d culture in vitro was evaluated. Results Compared with the common bile duct puncture group, the islet yield in the combined injection group was significantly increased (P < 0.001). The success rate of islet extraction in both groups was 83% with no statistical significance (P > 0.05). The islets extracted by common bile duct puncture combined with in situ pancreatic injection had intact morphology, high purity and high activity. The survival rate of newly isolated islets was nearly 100% after 24 h culture in vitro. After 1~5 d culture in vitro, the islet cells survived well. After 6 d culture in vitro, the islets showed central death. After culture in vitro for 24 h and 4 d, the islet function of the mice was normal after high glucose stimulation. Conclusions Common bile duct puncture combined with in situ pancreatic injection can increase the islet yield, and the obtained islet cells have high activity and proper function.

Sonic hedgehog inhibition induces mouse embryonic stem cells to differentiate toward definitive endoderm.

In the experimental group (shh inhibited group), there were significant decreases in the expression of Oct4, Nanog, Shh, GATA4, Brachyury and Goosecoid, while increases were observed for TAT and Pdx1. The expression of Sox17 did not differ between two control and experimental groups. In experimental group, the amount of GSC positive cells was somehow lower but it seems that there was no difference for Sox17. Shh inhibition induces ESCs to differentiate toward definitive endoderm by committing mesendodermal lineages.

Assessment of Mercury Contamination of Eloor Region of Periyar River in Kerala by Dithizone Method.

Pollution in Periyar River in Kerala is increasing rapidly and mercury is a major pollutant that is released by the industries situated on its banks. Mercury toxicity is difficult to diagnose and can eventually result in conditions such as Minimata disease if not controlled. An attempt has been made in this study to assess the extent of mercury contamination in the river by dithizone method and compare it with the maximum permissible level for river water. A comparison has also been attempted to assess the extent of mercury contamination of Periyar with that of other contaminated rivers of India. A total of 40 water samples each were collected from 10 different locations of Periyar river at surface level and at 1 metre depth. The samples were analysed by dithizone method of heavy metal extraction with the help of spectrophotometer. The mean mercury value obtained (at both levels) was 0.03 mg/L, which is 30 times more than the permissible level allowed in water (0.001 mg/L). The values obtained at 1m depth are slightly higher than at the surface. The mercury levels are comparable to that of polluted tributaries of other rivers such as Ganga and Yamuna in north India. It is imperative that the use of out-dated, inefficient methods of water treatment should be replaced with controlled release of mercury through separate sewer systems, and employing membrane cells, chitosan and granulated slag as adsorbents.

DESARROLLO DE MÉTODOS DE ANÁLISIS POR INYECCIÓN EN FLUJO A PARTIR DE PROCEDIMIENTOS CLÁSICOS: Determinación de Pb en agua / DEVELOPMENT OF FLOW INJECTION ANALYSIS METHODS BY CLASSICAL PROCEDURES: Determination of Pb in water / DESENVOLVIMENTO DE MÉTODOS DE ANÁLISE POR INJEÇÃO EM FLUXO A PARTIR DE PROCEDIMENTOS CLÁSSICOS: determinação de Pb em água

El análisis químico día a día se acerca más a la automatización, buscando satisfacer las necesidades actuales de resultados rápidos y confiables. Los sistemas de análisis en flujo (FIA - Flow Injection Analysis) son una de las formas de aproximarse a la automatización. En este artículo se presentan los pasos necesarios para implementar una metodología FIA, para la determinación de Pb(II) en agua, partiendo de la revisión de los procedimientos clásicos y describiendo detalladamente los pasos necesarios para implementar la técnica de análisis en flujo. El trabajo produjo un método de análisis de Pb en agua que usa ditizona disuelta en isopropanol (agente cromogénico), en presencia de bromuro de cetiltrimetil amonio (CTAB), para solubilizar en agua el complejo, cuyas características más sobresalientes fueron: volumen de inyección de muestra de 81,7 µL, velocidad de flujo de 8,0 mL/min, tiempo de toma de espectros 1,4 s e intervalo lineal de 1,0 a 40 mg L-1.

Chemical analysis has evolved towards automation to satisfy the current requirements: fast analysis and certainty in the results. Flow injection analysis (FIA) is a way to reach automation. This work presents the necessary steps to obtain an optimized FIA methodology for the determination of Pb(II) in water by classic methods. The result was a FIA method to determinate Pb with dithizone (chromogenic agent) dissolved in iso-propyl alcohol, using cethyltrimethylammonium bromide (CTAB) to solubilize the complex. The main characteristics of the method were: injection sample volume 81.7 µL, flow 8.0 mL/min, spectra acquisition time 1.4 s and linear range 1 to 40 mg L-1.

Cada dia, a análise química é mais cerca da automatização com o fim de satisfazer as necessidades atuais de resultados rápidos e confiáveis. Os sistemas de análise em fluxo (FIA - Flow Inyection Analysis) são uma das formas de aproximação à automatização. Este artigo apresenta os passos necessários para implementar uma metodologia FIA para a determinação de Pb(II) em água, partindo da revisão dos procedimentos clássicos e descrevendo detalhadamente os passos necessários para implementar a técnica de análise em fluxo. Os resultado são um método de análise de Pb em água que usa ditizona dissolvida em isopropanol (agente cromogénico) na presença de bromuro de cetiltrimetil amônio (CTAB), usado para solubilizar o complexo em água. As características principais do método foram: volume de injeção de amostra de 81,7 µL, velocidade de fluxo de 8,0 mL min-1, tempo de aquisição de espectros de 1,4 s e intervalo linear de 0.9 a 40 mg L-1.

Rapid Determination of Lead in Air by Water Phase Solubilization Dithizone Photometry / 环境与健康杂志

Objective To establish a method for rapid determination of the lead in air by water phase of solubilisation dithizone photometry. Methods The lead in air was determined by water phase solubilisation dithizone photometry with Tween20 as the solubilizer. Results The linear range was 1.0-100 mg/L(r≥0.999),RSDs were 1.36%～9.57%,the recovery rates were 97.4%-98.3%,the lowest detected concentration was 0.003 mg/m3. There was no significant difference between the result of this method and that of colorimetry. Conclusion The method was rapid,accurate and sensitive,this method is suitable for rapid determination of lead in the air.

Determination of Trace Cadmium in Water by Anodic-Stripping Voltammetry Using Dithizone-Modified Glassy Carbon Electrode / 环境与健康杂志

Objective To establish an anodic-stripping voltammetry method for determination of trace cadmium in water using dithizone-modified glassy carbon electrode. Methods Cd2+ was preconcentrated on the surface of the dithizone-modified glassy carbon electrode at -1.21 V, and subsequently reduced to Cd on the electrode. When the electric potential of electrode increased from -1.21 V to -0.30 V, the reduced cadmium was oxidized and stripped from surface of electrode, and the sensitive anodic-stripping peak was observed at -0.79 V. The parameters including the selection of supporting electrolytes, pH value, the amount of dithizone, concentration electric potential and time were optimized. Results The most suitable reaction medium was 0.1 mol/L NaAc-Hac-KI solution at pH value of 3.00.The most suitable volume of 1g/L methenyl chloride-dithizone solution was 10 ?l. The optimized concentration electric potential and time were -1.21 V and 5 min respectively. The linear range of this method was 5?10-8-2?10-6 mol/L. The average recovery rate was 98.42%. The relative standard deviation was 2.90%(n=8). The detection limit was 6?10-9 mol/L. Conclusion The method was simple ,rapid and sensitive,which was suitable for the determination of trace cadmium in practical water sample.

EFFECTS OF DITHIZONE ON Zn METABOLISM IN MATERNAL RATS AND THE DEVELOPMENT OF BRAIN OF THEIR PUPS / 西安交通大学学报(医学版)

The changes of zine content in serum and feces observed after intragastric administration of a certain dose of dithizone to the pregnant rats in their third trimester for one week, and the developing status of brain of their pups were studied. The result showed that the total fecal exerction of zine during 24 hours increased and serum zine content decreased significantly aftcr continual administration of dithizone for one week in maternal rats. It suggested that dithizone may be used for making animal model of zine deficiency. The body and brain weights, brain protein content and RNA/DNA ratio of the newborn delivered by the zine-deficiency maternal rats decrcased significantly. This indicates that the maternal zine dificiency in third trimester gives side effects on the development of their fctal brain.