Establishment of an infected necrotizing pancreatitis model by retrograde pancreatic duct injection of sodium taurocholate and E. coli in rats / 华中科技大学学报（医学）（英德文版）

A stable and reliable infected necrotizing pancreatitis (INP) model in rats was established in order to study the pathophysiological mechanism and pathological development rule of INP and explore the new therapeutic methods for the diseases. Forty-six SD rats were randomly divided into 5 groups. The animals in group A received the injection of 5% sodium taurocholate into the pancreatic duct and those in group B underwent that of E. coli into the pancreatic duct. The rats in groups C, D and E were subjected to the injection of 5% sodium taurocholate in combination with different concentrations of E. coli (10(3), 10(4), 10(5)/mL, respectively) into the pancreatic duct. The dose of injection was 0.1 mL/100 g and the velocity of injection was 0.2 mL/min in all the 5 groups. Eight h after the injection, the survival rate of animals was recorded and the surviving rats were killed to determine the serum content of amylase and perform pathological examination and germ cultivation of the pancreatic tissue. The results showed that acute necrotizing pancreatitis model was induced by injection of 5% sodium taurocholate into the pancreatic duct. The positive rate of germ cultivation in group A was 12.5%. The acute necrotizing pancreatitis model was not induced by injection of E. coli into the pancreatic duct and the positive rate of germ cultivation in group B was 0. The INP model was established in groups C to E. The positive rate of germ cultivation was 60%, 100% and 100% and 8-h survival rate 100%, 100% and 70% in groups C, D and E, respectively. It was concluded that a stable and reliable model of INP was established by injection of 5% sodium taurocholate in combination with 10(4)/mL E. coli into the pancreatic duct with a dose of 0.1 mL/100 g and a velocity of 0.2 mL/min. The pathogenesis of INP might be that the hemorrhage and necrosis of pancreatic tissue induced by sodium taurocholate results in weakness of pancreatic tissue in fighting against the germs. Meanwhile, the necrotic pancreatic tissue provides a good proliferative environment for the germs.

Comparison of Cryptosporidium parvum development in various cell lines for screening in vitro drug testing.

This study describes the development of Cryptosporidium parvum in MDCK, MA-104, Hep-2 and Vero cell lines. Differences in susceptibility, infectivity, and the methodology of excystation were determined. Various solutions were considered to determine the factors which enhanced the excystation (eg with and without sodium hypochlorite, trypsin or sodium taurocholate). It was shown that the sporozoites could be excysted in media either with or without trypsin and sodium taurocholate, but the number of sporozoites in the latter solution was less than the former one. Only oocysts digested by sodium hypochlorite and trypsin can enter the culture cells. Numerous meronts and oocysts were demonstrated and persisted for 9 days. Asexual stages were not observed in MA-104. Only few oocysts could be detected 1-3 days post-inoculation. There was a significant difference between the number of oocysts, which invaded MDCK, MA-104, and Hep-2 cells. MDCK gave the highest susceptibility to oocyst invasion among the three cell lines and asexual stages were also found. Among the 25 isolates, which had been cultivated, 23 isolates could infect MDCK and Hep-2. Only 2 isolates could not infect the MDCK cell. These 2 isolates could infect the Vero cell and yielded high numbers of trophozoites. Praziquantel (PZQ), doxycycline, and paromomycin (PRM) were tested on the infecting parasites. The drugs were added either with the inoculum or 24 hours after inoculation. None of them was effective, including PRM, which had been previously reported as effective.

Efeito protetor da reduçäo do conteúdo enzimático do pâncreas na lesäo pulmonar da pancreatite aguda / Protective effect of reduction of pancreatic enzyme content on the pancreas in acute pulmonary pancreatitis

A lesao pulmonar surge em até 50-70 por cento dos pacientes com pancreatite aguda. A infusao de ceruleína em doses fisiológicas reduz o conteúdo enzimático do pâncreas com diminuiçao da taxa de mortalidade da pancreatite. Com objetivo de avaliar o efeito da reduçao do conteúdo enzimático do pâncreas sobre a lesao pulmonar da pancreatite aguda, foi induzida pancreatite em ratos Wistar através da infusao, dentro do ducto biliar, de soluçao de taurocolato de sódio a 5 por cento: grupo I, ratos com pancreatite; grupo II, ratos nos quais pancreatite foi induzida somente após reduçao do conteúdo enzimático do pâncreas, e grupo III, controle. A lesao pulmonar foi avaliada através da utilizaçao do corante azul de Evans, sendo menor no grupo II comparativamente ao I (P O,05). Especula-se que a reduçao do conteúdo enzimático do pâncreas diminui a lesao pulmonar da pancreatite aguda pela reduçao da quantidade de enzimas que atinge a circulaçao sistêmica.

Protective effect of a protein-free diet in acute experimental pancreatitis

1. Surgical time, amylase activiry and pancreatic protein, DNA and RNA content were measured in 38 control rats and in 104 rats injected with sodium taurocholate to induced acute pancreatitis after 21 days on one of four diets differing in protein, lipid and carbohidrate cocnent. 2. All of the parameters measured were lower in rats with pancreatitis than in controls maintained on thes same diets. Among the rats with pancreatitis, those reciving a protein-free survived longer and had significantly higher DNA, lower amylase activity and lower RNA and protein levels than those reciving a balanced diet or one that was high in protein or lipid content. 3. We conclude that acute pancratitis in rats has a more benign course in protein-undernourished animals

Early changes in bile secretion following relief of short-term biliary obstruction in the rat

Se estudiaron los efectos que produce una obstrucción biliar extrahepática de 2 h en la rata después de liberada la interrupción del flujo biliar (FB). Las actividades plasmáticas de fosfatasa alcalina y 5'-nucleotidasa aumentaron luego de la obstrucción. El aumento de la coleresis post-obstructiva fue debido a la mayor excreción biliar de ácidos biliares acumulados durante la obstrucción, la cual no fue acompañada por otros lípidos, como ocurre en ratas normales. La inyección en bolo de taurocolato de sodio (TC) puso de manifiesto una capacidad disminuida pra ser secretado en bilis y además, una disminución de la eficiencia colerética. A su vez, las ratas post-colestásicas mostraron una gran susceptibilidad al efecto inhibitorio del TC sobre el FB independiente de sales biliares. Dichas alteraciones podrían reflejar importantes daños en la membrana ocasionados por la salbiliar excretada, a pesar del corto período de la obstrucción, así como que las alteraciones observadas del FB dependiente e independiente de sales biliares pueden ser atribuidas a una incapacidad para reparar membranas en las ratas post-colestásicas