In order to study the influence of biliary tract obstruction on enteromicroflora,we ligate the canine biliary tract to observe the acrobic and anerobic bacteria in the duodenum and ileum at intervals of post-ligation(the 10th,20th,30th days),and to study the pathogenesis and ultramicroscopic of the ileal mucosa at the same intervals.The results showed that:the population and species of enteroflora in small intestine gradually increased after biliary obstruction.Bacteria(especialy E.coli) ascended to the upper part of small intestine,from their normal habitant of lower part of small intestine.Therefore the radio of general aerobia and E.coli risen obviously in duodenum.The longer the obstruction,the more pathologic changes were observed in ileal mucosa.such as edema,leukocytes infiltration and destruction of epithelial villi.All of those changed may be the causative factor of biliary tract infection.So that,in the programs of preventing enterogenic infection at the state of biliary tract obstruction,the protection and adjusting of normal enteroflora should be adventently considered.
Objective To verify adhesion and growth ability of canine esophageal epithelial cells (EECs) on the poly (lactic-co-glycolic acid) (PLGA), a three-dimensional biodegradable polymer scaffold, and to reconstruct the canine esophagus by the tissue engineering. Methods Free canine EECs isolated from adult dogs by esophagoscopy were seeded onto the PLGA scaffolds precoated with collagen type Ⅳ after the first passage by the in vitro culture. Then, the composites of the cell-scaffold were respectively cultured invitro and in the abdominal cavity of the dog in vivo. After different periods, the cell-seeded scaffolds were assessed by histological HE staining, scanning electron microscopy, and immunohistochemical analysis. Results The cells displayed a cobblestone-shaped morphology that was characteristic of the epithelial cells and were stained to be positive for cytokeratin, which indicated that the cells were EECs. The canine EECs were well distributed and adhered to the PLGA scaffolds, and maintained their characteristics throughout the culture period. After the culture in vivo for 4 weeks, the cell-seeded scaffolds looked like tissues. Conclusion PLGA scaffolds precoated with collagen type Ⅳ can be suitable for adhesion and proliferation of EECs, and can be used as a suitable tissue engineering carrier of an artificial esophagus.
Objective o study the feasibility of homologous vascularized nerve transplantation after ultra deep cryopreservation. Methods Vascularized sciatic nerve from 12 female dogs was transplanted after ultra deep cryopreservation. Fortyeight male dogs were divided into 4 groups: ultra deep cryopreservation homologous vascularized nerve (group A), ultra deep cryopreservation homologous nerve (group B), fresh homologous vascularized nerve (group C), and fresh autologous vascularized nerve (group D). The gross appearance, patency rate of arteryand morphological transplanted nerve were observed 1, 4 and 12 weeks after transplantation respectively. Immunological analysis was performed using IL 2 assay and T lymphocyte subpopulations assay after 4 weeks. Image pattern analysis andelectromyogram were observed after 12 weeks. Results In groups A and D, no toe ulcer occurred, the atrophy of later limb and the sense of pain from skin of calf were restore significantly in the postoperative 12th week. In groups B and C, toe ulcer occurred, the atrophy of later limb and the sense of pain from skin of calf were not restored significantly in the postoperative 12thweek. The vessel patency rate of groups A and D was 83.3%, which was significantly higher than that of group C (50%,Plt;0.05). The changes of IL2 and Th, Ts in group C were significantly higher than that in groups A,B,D(Plt;0.01). There were increased vessel and regenerated nerve in transplanted nerve under optical microscope and image pattern analysis in groups A and D. There were shorter latent period of motor evoked potential, greater amplitude of action potenlial and faster motor nerve conducting velocity in groups A and D after 12 weeks. Conclusion The antigenicity of the homologous never and vessel may be reduced significantly by being frozen, and cryopreserved vascularized nerve can transferred successfully without the use of immunosuppressive agents. Vascularized nerve may restore good significantly for the thick nerve.
To find the relation between the damage of gastric remnant mucosal barrier and the precancerous lesion of gastric remnant mucosa, in the process of the canine gastric remnant precarcinogenesis induced by N-methyN’-nitro-N-nitrosoguanidine (MNNG), we performed regularly the esophagogastroscopy and the mucosal biopsy.At the same time, we also measured gastric transmucosal potential difference and intracellular DNA content of remnant mucosa.We found that the more severe the damage of gastric remnant mucosal barrier was , the greater the malignant capacity of gastric remnant mucosal was.Our study suggests that the damage of gastric remnant mucosal barrier plays an important role in the gastric remnant mucosal precarcinogenesis.
Objective To investigate an improved large vascular reconstruction method in the canine liver transplantation and see whether it can shorten the anheptic time and thus reduce the harmful effects during the anhepatic phase. Methods Thirty-two mongrel dogs were enrolled and divided into two groups randomly:the donor group (n=16) and the acceptorgroup(n=16). The dogs in the acceptor group were divided into two groups, according to the different reconstruction methods: Group A using the magnetic rings for a large vein reconstruction in the canine liver transplantation (n=10), and Group B using a handsewing large vein reconstruction in the canine liver transplantation (n=6). The operation time, hemodymics change, anastomosis site, and survival were observed. Results The operation time was as follows: In Group A, the total operation time, the inferior vena cava anastomosistime, and the anheptic phase time were significantly shorter than those in Group B (3.24±0.49 h vs 4.12±0.51 h，5.89±2.27 min vs 28.33±6.04 min，3.89±0.73 min vs 12.16±3.72 min),with a significant difference between the two groups (Plt;0.01). The haemodymics changes were as follows: In Group A, MAP dropped during the anhepatic phase, but it soon recovered after reperfusion，and there was only 730.56±150.56 ml of fluid including the donor blood that needed to be transfused, with no pressor agent required. In Group B, blood pressure dropped during the anhepatic phase，but it slowly recovered，and there was 2241.67±390.78 ml of fluid. In Group A, all the stomas had no errhysis, twistor thrombus. The twisted stomas could be corrected by the revolving of the magnetic rings. The endangium at the site of anastomosis was smooth. In Group B, most of the stomas had errthysis. In Group A, 3 dogs survived for more than 7 days, 6dogs survived for 3-6 days, and 1 dog survived for only 12 hours. In Group B, 2 dogs survived for 3-6 days, 3 dogs survived for 1-2 days, and 1 dog survivedfor only 12 hours. Conclusion Using the magnetic rings for a large vascular reconstruction in the canine liver transplantation is an improvedmethod, which can simplify the anastomosis procedures and significantly shortenthe anheptic phase time. However, the magnetic rings have to be placed in the abdomen, so this method remains to be further improved.
To evaluate the effect of technique combination of implant-retented titanium lattice with decalcified dental matrix (DDM) implanting. Methods Six healthy male dogs (weighing of 10-20 kg) were randomly divided into 3 groups. All the premolars were extracted on both sides of the jaw in dogs. After 2 weeks, titanium lattice and implant were implanted in the maxillary premolar region with DDM on one side (experimental group), but without on the other side (control group) of each dog. After 4, 9 and 14 weeks, respectively, 2 animals were individually killed each time, and the samples wereevaluated by general observation, X-ray examination, histological observation and histomorphometric analyses. Results General observation: Among the 6 dogs, there was no postoperative infection or death. The X-ray examination showed that the bone density of the experimental group was greater than the control group at 4 and 9 weeks, and had no significant difference as to the vicinity bone at 14 weeks. On the other hand, the density of the control group was very low under the titanium lattice and around the implant. The experimental group revealed a ridge augment of (1.93 ± 0.24) mm, and control group (-1.02 ± 1.20) mm (P lt; 0.05). Developed bone sponge could be found after 14 weeks. Histological observation showed that in the experimental group, the DDM surface was nearly absorbed at 4 weeks. A few new bones were formed at 9 weeks. The whole DDM was absorbed; the trabecular bone was thick and arranged regularly; and the intergradations of implant were observed at 14 weeks. In the control group, there were some inflammatory fibers around the neck of implant at 4 weeks. The inflammatory condition extended to the root of implant and the titanium lattice at 9 weeks. There was no newly-formed bone under the titanium lattice at 14 weeks. Histomorphometric analyses showed that the implant contact bone ratio approached 1 ∶ 1, and showed no significant difference between the new bone fragment and former bone fragment in the experimental group. Conclusion This augmentation of alveolar ridge evaluated by the study is appl icable, but further study is necessary.
Objective To establish and evaluate a hydrocephalus model in dogs. Methods Twelve healthy adult male mongrel dogs (weight, 10-15 kg) were randomly divided into the control group (n=6) and the experimental group (n=6). All the dogs were given CT and neurological examination to exclude congenital ventricular enlargement and neurological abnormity before they received hydrocephalus induction. Surgical procedures included the exposing of the foramen magnum area, the opening of the atlantooccipita anadesma, and the injecting of silicone oil (0.3 ml/kg) into the fourth ventricle through a silicone tube. Normal saline was injected in the control group. The Tarlov neurological fitness assessment and the Evan’s ratio were used to evaluatethe degree of hydrocephalus at 3, 14 and 56 days after operation. Results In the experimental group, the dogs were dull and unsteady in walking,and they drank and ate less. The lateral ventricle began to expand 3 days afteroperation, and then the temple horn of the lateral ventricle and the third ventricle were also affected 14 days after operation. The ventricles were enlarged progressively after operation. The Tarlov scores measured at 3, 14 and 56 days afteroperation had a significant difference at the same time point between the control group(5.83±0.75，6.50±0.55，6.00±0.63) and the experimental group (4.00±0.89，4.83±1.17，4.50±1.05，P＜0.01), but had no significant difference within the same group at different time points (P＞0.05). The Evan’s ratios measured at 3, 14 and 56 days after operation were 0.33±0.04,0.39±006，0.44±0.03，respectively,in the experimental group; and were 0.27±0.06，0.25±0.09, 0.26±0.05,respectively,in the control group. There was a significant difference atthe same time point between the two groups, and at different time points within the experimental group (P＜0.05).Conclusion The dog model of hydrocephalus induced by the injecting of silicone oil into the fourth ventricle has a highsuccess rate, and the model is appropriate for the studies on diagnosis and therapy of hydrocephalus.
目的 建立犬开放性气胸海水浸泡的实验模型 ,探讨实验动物早期死亡原因。 方法 2 0条健康成年杂种犬随机分为两组。对照组 :实验动物受伤后直接观察 ;实验组 :动物受伤后置入人工配制的海水中。监测血流动力学、呼吸、血液渗透压、血液电解质、动脉血气变化以及肺部病理改变。 结果 实验组死亡率明显高于对照组 ,平均生存时间为 45分钟。实验组经海水浸泡后有急性呼吸和循环功能衰竭、严重电解质平衡紊乱、高渗血症、重度肺损伤以及严重代谢性和呼吸性酸中毒。 结论 开放性气胸后海水浸泡可引起一系列严重的病理生理变化 ,其结果是导致实验动物早期死亡的重要原因。
To evaluatae the role of cathepsin B in the pathogenesis of acute pancreatitis. The experimental dogs were divided into three groups based on the severity. An acute edematous pancreatitis group (n＝11), an acute hemorrhagic necrotizing pancreatitis group (n＝12), and a control group (n＝7). Distribution of cathepsin B in pancreatic aciner cell was studied. Results: there was a redistribution of cathepsin B from the lysosomal fraction to the zymogen fraction. The results indicated that cathepsin B play a important role in the pathoagenesis of acute pancreatitis.
Objective It is a thorny problem to reconstruct long ureteral defect in urinary surgery. To investigate the feasibil ity of intestinal sero-muscular segment with autograft of bladder mucosa as a replacement material for reconstructionof long ureteral defect. Methods Twelve adult Beagle dogs (weighing 6.5-9.3 kg and being male or female) were randomlydivided into 3 groups, each group including 4 dogs. In group A, lower segment of ureter was reconstructed by autograft of bladder mucosa to the intestinal sero-muscular segment; furthermore, the proximal and distal reconstructed ureter were anastomosed to the bladder and the upper ureter, respectively. In group B, upper segment of ureter was reconstructed by the same method as that of group A, the proximal and distal reconstructed ureter anastomosised with pelvic and lower ureter, respectively. In group C, whole ureter was reconstructed by the same method as that of group A, the proximal and distal reconstructed ureter were anastomosised with pelvic and bladder, respectively. Blood urea nitrogen, Cr2+, K+, Na+, Cl-, Ca2+ and carbon dioxide combining power were detected before operation, the general state, drainage volume, heal ing of wound, and compl ications were observed after operation. At 6 weeks, the blood biochemical indexes and intravenous urography (IVU) were detected, and the gross and histological observations of ureter were done. Results In group B, urine leakeage and infection occurred in 1 dog 2 days after operation because ureter stent prolapsed; other dogs had no complications. There was no significant difference in the biochemical indexes between before operation and 6 weeks after operation. IVU showed: in group A, hydronepherosis and ureterectasia occurred on the operation side of 1 dog; in group B, anastomotic stricture between the reconstructed ureter and lower ureter and hydronepherosis occurred in 1 dog; and in other dogs of all groups, renal function was good and the reconstructed ureter had peristalsis function. The histopathological observation showed that the reconstructed ureter had similar structure to normal ureterat 6 weeks in 3 groups; the inflammatory cells infiltrating of the reconstructed ureter was observed in 1 dog of groups A and C, respectively. Conclusion Reconstruction of ureter by intestinal sero-muscular segment with autograft of bladder mucosa has similar structure and function to the normal ureter. The results might provide an experimental basis for cl inical use.