A stable rat model of obstructive jaundice reversed by internal bile drainage using microsurgical techniques / 中国现代普通外科进展

Objective:To better understand the pathogenesis of obstructive jaundice (O J),a variety of rat OJ and biliary drainage models have been tried;however,complications are still common.We aimed to establish a stable rat model of OJ using microsurgical techniques,and to assess its reversal by internal bile drainage(IBD).Methods:After the pilot study,we developed a standardized surgical procedure.All operations were carried out under an operating microscope.In the first laparotomy,the proximal common bile duct (CBD) of the rat was ligated and transected.A tube was introduced into the distal end of the duct,and the other end of the tube was sealed and fixed.In the second laparotomy,the drainage tube was inserted into the (by now markedly dilated) proximal CBD,and ligated into position.We evaluated the general condition of the rats,the status of the liver and pancreas before and after IBD.Results:Complications such as intestinal reflux and bile duct blockage,were not found.Pancreatic injury was not evident by day 4 after the first laparotomy.After biliary drainage,the serum glucose and albumin concentration rapidly returned to normal levels.Liver weight/body weight ratio increased.The biochemical indicators and ultrasonographic elastography results for the liver gradually returned to normal.Conclusion:Using microsurgical techniques,we have developed a stable rat model of OJ reversed by IBD.

A simple rat model of in situ reversible obstructive jaundice in situ reversible obstructive jaundice model

PURPOSE: To develop a simple and reliable rat model of in situ reversible obstructive jaundice with low morbidity and mortality rates. METHODS: Rats were divided into 4 groups with 8 rats each: the sham-operated (SH) group only underwent laparotomy, the control internal drainage (ID-C) group underwent choledochoduodenostomy, the new internal drainage (ID-N) group and the long-term internal drainage (ID-L) group underwent choledochocholedochostomy. Common bile duct ligation was performed in all the drainage groups 7 days before reversal procedures. All rats were sacrificed for samples 7 days after the last operation except rats of the ID-L group that survived 28 days before sacrifice. Body weight, liver function, histopathological changes, morbidity and mortality were assessed. RESULTS: One rat died and 2 rats had complications with tube blockage in the ID-C group. No death or complications occurred in the ID-N and ID-L groups. The drainage tube remained patent in the long-term observation ID-L group. Body weight showed no significant difference between the ID-C and ID-N groups after 7 days drainage. Liver function was not fully recovered in the ID-C and ID-N groups after 7 days drainage, but statistical differences were only observed in the ID-C group compared with the SH and ID-L groups. Periportal inflammation and bile duct proliferation showed severer in the ID-C group than in the ID-N group. CONCLUSION: The present study provided an efficient, simple, and reliable rat model that is especially suitable for long-term or consecutive studies of reversible obstructive jaundice.

A simple rat model of in situ reversible obstructive jaundice in situ reversible obstructive jaundice model

PURPOSE: To develop a simple and reliable rat model of in situ reversible obstructive jaundice with low morbidity and mortality rates. METHODS: Rats were divided into 4 groups with 8 rats each: the sham-operated (SH) group only underwent laparotomy, the control internal drainage (ID-C) group underwent choledochoduodenostomy, the new internal drainage (ID-N) group and the long-term internal drainage (ID-L) group underwent choledochocholedochostomy. Common bile duct ligation was performed in all the drainage groups 7 days before reversal procedures. All rats were sacrificed for samples 7 days after the last operation except rats of the ID-L group that survived 28 days before sacrifice. Body weight, liver function, histopathological changes, morbidity and mortality were assessed. RESULTS: One rat died and 2 rats had complications with tube blockage in the ID-C group. No death or complications occurred in the ID-N and ID-L groups. The drainage tube remained patent in the long-term observation ID-L group. Body weight showed no significant difference between the ID-C and ID-N groups after 7 days drainage. Liver function was not fully recovered in the ID-C and ID-N groups after 7 days drainage, but statistical differences were only observed in the ID-C group compared with the SH and ID-L groups. Periportal inflammation and bile duct proliferation showed severer in the ID-C group than in the ID-N group. CONCLUSION: The present study provided an efficient, simple, and reliable rat model that is especially suitable for long-term or consecutive studies of reversible obstructive jaundice.

Establishment of a stable mouse model of brain death by the method of the gradually increasing intracranial pressure / 中国医学科学院学报

<p><b>OBJECTIVE</b>To establish a stable and modified mouse model of brain death (BD) and to share our experiences in BD induction and maintenance.</p><p><b>METHODS</b>Totally 35 C57BL/6 male mice were randomized into BD group (n=25) or sham control group (n=10). BD was induced by inserting a 2F Fogarty catheter connected to a syringe pump after trepanation of the left frontoparietal area and injecting volume at the speed of 6 μl/min until spontaneous respiration ceased. BD was diagnosed by electroencephalogram, apnea testing,as well as testing of brain stem reflexes. Mechanical ventilation was performed by orotracheal intubation. Right carotid artery was intubated by a PE-10 cannula for the continuous monitoring of mean blood pressure (MAP) and heart rate (HR). The right external jugular vein was catheterized for volume resuscitation.The sham control group underwent the same procedure with catheter insertion but without balloon inflation.Livers were removed and fixed in paraffin to evaluate the histological alterations with the light microscopy.</p><p><b>RESULTS</b>Mouse models of BD were successfully established about 20 minutes after balloon inflation, and the mean balloon volume at the time of BD was (105.77 ± 21.57)μl. The MAP and HR rapidly increased on occurrence of BD and the peak value was (128.28 ± 17.16) mmHg and (434.16 ± 55.75) beat/min, respectively, which were significant higher than those in the sham control group at the same time point (P=0.000). During the 4-hour follow-up time, MAP and HR in 72% (18/25) of BD animals remained haemodynamically stable. No animal died due to anesthesia and surgical operation.Hepatic tissues in BD mice showed mild focal ischemic damages (cellular edema, congestion, and inflammatory infiltration), which were slighter and fewer in sham control group.</p><p><b>CONCLUSION</b>The mouse model of BD was successfully established with lower surgical difficulty and can be performed in a standardized, reproducible and successful way.</p>

Transient hepatic venous occlusion induced liver hemodynamic change and reperfusion injury in rats / 中国医学科学院学报

<p><b>OBJECTIVE</b>To observe the hemodynamic change and reperfusion injury cause by transient hepatic venous occlusion and transient hepatic inflow occlusion in rats.</p><p><b>METHODS</b>The rat liver was divided into 3 different areas: the ischemia reperfusion (IR) area: the inflow of the right superior lobe was clamped for half an hour; the non-isolated lobe congestive reperfusion (NIL-CR) area: the outflow of the right median lobe was clamped for half an hour; and the isolated lobe congestive reperfusion (IL-CR) area: the outflow of the left lobe was clamped for half an hour. The flux value and the oxygen saturation of microcirculation were monitored before at clamping for 30 minutes, and on 1 day, 3 days ,and 7 days after reperfusion. The hepatic damage and Suzuki's score were evaluated.</p><p><b>RESULTS</b>After clamping for 30 minutes, the flux value in the IR area was significantly higher than in NIL-CR area (P<0.01) and IL-CR area (P<0.01), the oxygen saturation in the IR area was significantly higher than in NIL-CR area (P<0.01) and IL-CR area (P<0.05). Compared with IR area, both NIL-CR area and IL-CR area were found having more severe liver damage in terms of Suzuki's score in early postoperative period (at clamping for 30 minutes and on 1 day, P<0.01). However, there was no significant difference between NIL-CR area and IL-CR area in flux value, oxygen saturation, and Suzuki's score (P>0.05).</p><p><b>CONCLUSIONS</b>Hepatic venous occlusion can more effectively decrease the blood perfrusion and oxygen saturation; thus, compared to the IR, CR can result in more severe liver damage. The presence of normal liver tissue around the congestion area can not influence liver damage in transient hepatic venous occlusion.</p>

Effects of different hepatic inflow occlusion methods on liver regeneration following partial hepatectomy in rats / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the effects of different hepatic inflow occlusion methods on liver regeneration in rats after partial hepatectomy (PH).</p><p><b>METHODS</b>Male Wistar-Furth rats were randomly assigned to three groups: control group, underwent 68% hepatectomy alone; occlusion of portal triad (OPT) group, subjected to occlusion of portal triad under portal blood bypass; and occlusion of portal vein (OPV) group, subjected to occlusion of portal vein under portal blood bypass. Blood flow was occluded for 20, 30, and 40 minutes before 68% hepatectomy. According to the 7-day survival of each group, a same occlusion time T was set. Each group was divided into two subgroups (n = 8), in which animals were killed 3 and 7 days later. Liver regeneration was calculated as a percent of initial liver weight. Immunohistochemistry for proliferating cell nuclear antigen (PCNA) and Ki-67 was performed to quantify proliferating cells. In addition, functional liver volume represented by 99Tc(m)-GSA radioactivity was assessed.</p><p><b>RESULTS</b>The safe tolerance limit time was 30 minutes for OPT group and 40 minutes for OPV group. At 3 days after PH, no significant difference was observed in the regeneration rate of each group (P > 0.05). However, liver radioactive activity, PCNA labeling index, and Ki-67 index of OPV group was significantly higher than those of OPT group (P < 0.05); the latter were similar to those of control group (P > 0.05). At 7 days after PH, no significant difference was observed in all indexes among three groups (P > 0.05).</p><p><b>CONCLUSION</b>Compared with Pringle maneuver, preserving the hepatic artery flow during portal triad blood inflow occlusion can promote remnant liver regeneration early after PH.</p>

Experimental studies on the treatment of colon cancer by cytosine deaminase gene and 5-fluorocytosine / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effect of cytosine deaminase (CD) gene plus 5-fluorocytosine (5-Fc) on the growth of human colon cancer xenograftin nude mice.</p><p><b>METHODS</b>Retroviral vector expressing CD gene was transfected into human colon cancer SW1116 cells. Expression of the transfected CD gene in SW1116 (SWCD(2)) was confirmed by RT-PCR. The cytotoxicity of 5-Fc on SW1116 was determined by MTT assay in vitro. In vivo, the CD gene expression vector was injected intratumorally and 5-Fc was given by ip injections.</p><p><b>RESULTS</b>In vitro, SWCD(2) cells were killed by 5-Fc with an IC(50) of 66 micromol/L while the nontrasfected SW1116 cells needed an IC(50) of 16 000 micromol/L to be killed. The growth of SWCD(2) xenografts was significantly inhibited by systemic administration of 5-Fc.</p><p><b>CONCLUSION</b>CD gene/5-Fc system is a potential gene therapy strategy for human colon cancer.</p>

Protective effects of lidocaine injected into the hepatoduodenal ligament on warm ischemia-reperfusion injury to the rat liver / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Ischemia-reperfusion (IR) injury to the liver is still a critical and daunting problem in the field of hepatobiliary surgery. Ischemic preconditioning (IP) of the liver serves as an effective approach against IR injury. This study was to develop a novel procedure that could mimic IP, but might be more feasible than IP during surgery.</p><p><b>METHODS</b>Eighty-two SD rats were randomly divided into 5 groups. L group (n = 21): 0.4% lidocaine (10 mg/kg) was injected into the hepatoduodenal ligament 10 minutes before a 40-minute hepatic IR. IP group (n = 16): a 5-minute ischemia was followed by a 10-minute reperfusion prior to a 40-minute hepatic IR. ILR group (n = 15): after a 40-minute ischemia of the liver, 0.4% lidocaine (10 mg/kg) was injected into the hepatoduodenal ligament 10 minutes prior to a 40-minute reperfusion of the liver. IR group (n = 15): the liver of the rat was subjected to a 40-minute IR. Control group (n = 15): 0.9% sodium chloride was injected into the hepatoduodenal ligament without other treatments. The levels of plasma alanine transaminase (ALT) and aspartate transaminase (AST) were determined for each group after treatment.</p><p><b>RESULTS</b>The mean concentrations of ALT and AST were (379.80 +/- 141.69) U/L and (606.05 +/- 220.26) U/L for the L group, (334.64 +/- 141.94) U/L and (625.68 +/- 267.06) U/L for the IP group, (523.36 +/- 170.35) U/L and (765.47 +/- 238.45) U/L for the ILP group, (524.29 +/- 163.59) U/L and (764.63 +/- 246.79) U/L for the IR group, and (150.90 +/- 27.05) U/L and (298.15 +/- 47.68) U/L for the control group (standard error of the mean).</p><p><b>CONCLUSION</b>A significant decrease in ALT and AST levels was observed in the L and IP groups when compared to the ILR and IR groups (P < 0.05), but no significant difference in ALT and AST levels was observed in the L group when compared to the IP group (P > 0.05). These results suggest that pretreatment with lidocaine injected into the hepatoduodenal ligament prior to IR provides effective protection against subsequent IR injury to the liver. The novel approach of blocking innervation with lidocaine mimics hepatic IP, but is more convenient than IP at the time of liver surgery.</p>