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.
The purpose of the study was to observe effect of chinese medicine “Qing Yi Tang” on the repair of injury of intestinal mucosa in acute necrotizing pancreatitis (ANP). Dogs ANP model were induced by injection of 5% sodium taurocholate (0.5 ml/kg) with 3 000 u/kg trypsin into the pancreatic duct. Diamine oxidase and anylase activity in blood, protein and MDA levels of ileal mucosa were to be determined in ANP and after treatment of “Qing Yi Tang”. Intestinal permeability was also to be studied, LPS and bacteria translocation (BT) were obseved. All animals were sacrificed on day 7, the tissue of ileal mocosa was collected for histological and ultrastructural studies. The results showed that after treatment with Chinese medicine “Qing Yi Tang”, the injury of intestinal mucosa in ANP reduced. The length, height, area and protein of ileal mucosa increased significantly, intestinal permenbility decreased, the levels of LPS reduced in 1-2 times, and organ BT rate also reduce in 50%. The results indicated that chinese medicine “Qing Yi Tang” had good effect on improving repair of intestinal mucosa injury, protecting gut barrier function, reducing the incidence of LPS and bacteria translocation.
Objective To make a comparison for the change of maximum tensile intensity and stiffness of a whole implant that is placed into bone tunnel with various lengths tendon, by using beagle dog’s autogenous flexor tendons to reconstruct anterior cruciate l igament (ACL). Methods Sixty male beagle dogs were included in the experiment (weighting 13-16 kg). Three dogs were used for intact flexor tendon of both knees (normal control group), 3 dogs for the intact ACL andfemur-graft-tibia complex (auto control group) and 54 dogs (108 knees) for models of reconstructed ACL (6 experimentalgroups according to different lengths of tendon: 5, 9, 13, 17, 21 and 25 mm in the bone tunnel). The tensile intensity and stiffness were measured after 45, 90 and 180 days separately after operation. Results In the normal control group, the maximum tensile intensity of the intact flexor tendon was (564.15 ± 36.18) N, the stiffness was (59.89 ± 4.28) N/ mm. In the auto control group, the maximum tensile intensity of the intact ACL was (684.75 ± 48.10) N, the stiffness was (74.34 ± 6.99) N/ mm, all ruptured through the intra-articular portion of the graft. The maximum tensile intensity of femur-graft-tibia complex in the auto control group was (301.92 ± 15.04) N, the stiffness was (31.35 ± 1.97) N/mm. After 45 days of operation, all failure occurred at the tibial or femoral insertion site. After 90 days of operation, 24 of the breakpoints were scattered in tendon-bone junction, 12 (3 in 17 mm group, 5 in 21 mm group, 4 in 25 mm group) ruptured through the intra-articular portion. After 180 days of the operation, all breakpoints were distributed inside joint of the implant. The maximum tensile intensity and the stiffness were ber in 17, 21 and 25 mm groups than in 5, 9 and 13 mm groups after operation (P lt; 0.05). Conclusion Tendon with 17 mm length, which will be implanted into bone tunnel, is an appl icable index, in reconstruction of ACL by autogenous tendons.
The model of acute hemorrhagic necrotizing pancreatitis (AHNP) was produced by retrograde forced injection of autogenous bile into the main pancreatic duct. The result showed that urgent surgical (transduodenal) intra-pancreatic duct drainage reduced the mortality rate of the experimental animals. Keeping the drainage patent and clear can both abate the pathological changes and promote the renovation of the dogs pancreas. So it can guide the clinical treatment in some way.
OBJECTIVE:To elucidate the nature of degenerations in canine peripheral retina and compare the degenerations with those in human peripheral retina. METHODS: Examining randomly the peripberal fundus of eighty eye balls of forty dogs wdh dissecting microscope. The lesions of degenerations were photographed and processed for light microscopic examination. RESULTS:Typical Cystoid degeneralion,reticular degenerative retinoschisis, paving-stone degeneration, and lattice degeneration were discovered. The pathologic findings of these degenerations were same as or similar to those of the degenerations in human peripheral retina. CONCLUSIONS:The atrophic retinal degenerations that are similar to human' s are present at peripheral fundus in canine eyes. （Chin J Ocul Fundus Dis,1996,12: 151-152）
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 To construct a new composite artificial trachea and to investigate the feasibility of trachea repair and reconstruction with the new composite artificial trachea transplantation in dogs. Methods The basic skeleton of the new composite artificial trachea was polytetrafluoroethylene vascular prosthesis linked with titanium rings at both ends. Dualmesh was sutured on titanium rings. Sixteen dogs, weighing (14.9 ± 2.0) kg, female or male, were selected. The 5 cm cervical trachea was resected to prepare the cervical trachea defect model. The trachea repair and reconstruction was performed with the new composite artificial trachea. Then fiberoptic bronchoscope examination, CT scan and three-dimensinal reconstruction were conducted at immediate, 1 month, and 6 months after operation. Gross observation and histological examination were conducted at 14 months to evaluate the repair and reconstruction efficacy. Results No dog died during operation of trachea reconstruction. One dog died of dyspnea at 37, 41, 55, 66, 140, and 274 days respectively because of anastomotic dehiscence and artificial trachea displacement; the other 10 dogs survived until 14 months. The fiberoptic bronchoscope examination, CT scan and three-dimensinal reconstruction showed that artificial tracheas were all in good location without twisting at immediate after operation; mild stenosis occurred and anastomoses had slight granulation in 6 dogs at 1 month; severe stenosis developed and anastomosis had more granulation in 1 dog and the other dogs were well alive without anastomotic stenosis at 6 months. At 14 months, gross observation revealed that outer surface of the artificial trachea were encapsulated by fibrous connective tissue in all of 10 dogs. Histological examination showed inflammatory infiltration and hyperplasia of fibrous tissue and no epithelium growth on the inner wall of the artificial trachea. Conclusion The new composite artificial trachea can be used to repair and reconstruct defect of the trachea for a short-term. Anastomotic infection and dehiscence are major complications and problems affecting long survival.
Objective To investigate the antibacterial and osteogenic capabil ities in vivo of hydroxyapatite (HA)/silver (Ag) coating. Methods HA/Ag coating (Ag qual ity percentage was 3%) and HA coating were deposited to external fixator Schanz screws. The tibial fracture model was establ ished in right hindl imb of 18 adult male Beagle dogs (weighing 15-20 kg). Thetibia was stabil ized with an external fixator and 2 Schanz screws of HA coating at proximal tibia (control group, n=18) and HA/Ag coating at distal tibia (experimental group, n=18), and every screw incision was infected with Staphylococcus aureus. Infection in screw holes and the changes of bone-screw interface were observed by wound grading and X-ray films. Results In control group, wounds infection became worse with time (χ2=13.492, P=0.001), while in experimental group, no obvious change was observed (χ2=0.208, P=0.901). The wound grading of experimental group was significantly better than that of the control group at 1, 2, and 3 weeks (P lt; 0.05). Laser scanning confocal microscope showed that there was bacterial adhesion on the surface of screws in 2 groups, viable becteria mainly in control group and non-viable becteria mainly in experimental group. The scanning electron microscope (SEM) observation results of the fractured sclerous tissue section showed that an obvious transparent boundary between screw and bone in control group, but no obvious boundary in experimental group. The osseointegration ratios were 76.23% ± 15.54% in control group and 93.42% ± 5.53% in experimental group, showing significant difference (t=8.843, P=0.000). The SEM observation showed that HA/Ag coating integrated with new bone and the surface of implant was filled with new bone in experimental group; obvious interspace was seen between the HA coating and new bone in control group. Conclusion HA/Ag coating has good antibacterial and osteogenic capabil ities, so it can take effects in preventing infection in screw holes and loosening of implants.
Objective To discuss the way of animal model building of hepaticocholedochostomy(HC) and hepaticojejunostomy(HJ) and to compare the short-term effect. Metheds Twenty-nine dogs were divided randomly into control group(n=5) and the experimental group (stenosis of left hepatic duct, n=24). After 7 weeksof stenosis of left hepatic duct,24 dogs in the experimental group were divided randomly into HC subgroup (n=12) and HJ subgroup (n=12) .The operation time and the blood loss during operation were recorded and the hepatic function was detected.Results The diameter of left hepatic duct was significantly expended after 7 week’s stenosis. Hepaticocholedochostomy took shorter time and lost less blood than hepaticojejunostomy. The dogs in HC subgroup lost less weight than thosein HJ subgroup. In HC and HJ subgroups, the mortality rates were 1/12 and 3/12;the infectious rates of incision were 3/12and 5/12 respectively. Serum levels of total bilirubin and transaminase increased significantly in the 7th week after stenosis of left hepatic duct compared with before stenosis of left hepatic duct. However, Serum levels of total bilirubin and transaminase restored to normallevels after 1 month of HC or HJ.Conclusion It is feasible to establish animal model of bile duct reconstruction on the basis of stricture of bile duct. The dogs undergoing hepaticocholedochostomy have less trauma, better results than the dogs undergoing hepaticojejunostomy. Both hepaticocholedochostomy and hepaticojejunostomy are able to relieve the obstruction of bile duct.
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.