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.
ObjectiveTo explore the possible factors which can influence the tiered medication situation in dog-bite clinic in comprehensive hospitals and village (community) health service centers, in order to provide references for the standardization of the diagnosis and treatment for dog-bite exposed patients.
MethodsWe conducted a retrospective observational study, searched the database of Dujiangyan Center for Disease Control and Prevention, and collected all the information of dog-bite patients administrated by village (community) health service center or hospital from January 2012 to December 2015.Then we investigated the patients' satisfaction and clinical workers' familiarity of dog-bite injury treatment protocols by questionnaires in March 2016.The data were analyzed with statistical description and chi-square test, to explore the possible factors which might influence the tiered medication situation for patients exposed to dog bite in Dujiangyan city.
ResultsThere was one comprehensive hospital and 27 township (community) health centers included in this study.During the study period, the total number and proportion of dog-bite injury patients admitted in the comprehensive hospital decreased year by year, especially for the number of grade-two dog-bite exposure patients.One the contrary, the total number and proportion of patients administrated by township (community) health service centers increased year by year, especially for the number (proportion) of grade-two and grade-three dog-bite exposure patients, which increased to 1 944(44.10%) and 1 248(28.31%), respectively.The results also showed that there were significant differences between the comprehensive hospital and township health centers in the satisfaction and familiarity investigation (P < 0.05).
ConclusionsTownship and village (community) health service centers are treating many more patients than the comprehensive hospital, but with a lower satisfaction rate.The distribution of dog-bite exposure patients visiting different degrees of hospitals are generally consistent with tiered medication policy.However, township and village (community) health service centers are recommended to strengthen the staff training about how to deal with dog-bite injuries standardly in order to improve patients' satisfaction.
【Abstract】 Objective To investigate the possibil ity of BMSCs seeded into collagen Ⅰ -glycosaminoglycan (CG)matrices to form the tissue engineered cartilage through chondrocyte inducing culture. Methods Bone marrow aspirate of dogs was cultured and expanded to the 3rd passage. BMSCs were harvested and seeded into the dehydrothemal treatment (DHT)cross-l inked CG matrices at 1×106 cells per 9 mm diameter sample. The samples were divided into experimental group and control group. In the experimental group, chondrogenic differentiation was achieved by the induction media for 2 weeks. Medium was changed every other day in both experimental group and control group. The formation of cartilage was assessed by HE staining and collagen Ⅱ immunohistochemical staining. Results The examinations under the inverted phase contrast microscopeindicated the 2nd and 3nd passage BMSCs had the similar morphology. HE staining showed the BMSCs in the experimental group appeared polygon or irregular morphology in the CG matrices, while BMSCs in the control group appeared fibroblast-l ike spindle or round morphology in the CG matrices. Extracellular matrix could be found around cells in the experimental group. Two weeks after seeded, the cells grew in the CG matrices, and positive collagen Ⅱ staining appeared around the cells in the experimentalgroup. There was no positive collagen Ⅱ staining appeared in the control group. Conclusion It is demonstrated that BMSCs seeded CG matrices can be induced toward cartilage by induction media.
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）
To evaluate the implantation effect of artificial vascular grafts with recombinant fibrinolytic enzyme factor II (rF II)-immobil ized lumina in animal test. Methods Four mm internal diameter (ID) polyurethane (PU) artificial vascular grafts were prepared by di pping and leaching method. The micro-pore size and morphology of the graft walls were observed by SEM. The graft lumina were immobil ized with rF II. Twenty hybrid male dogs [weighing (20 ± 1) kg] were used for animal model of carotid artery defect and were randomly divided into 3 groups: rF II -immobil ized PU group, no rF II -immobil ized PU group and expanded polytetrafluoroethylene (ePTFE) group. The vascular grafts were implanted for repairing injured segments of carotid artery in dogs. The general health state of animals was recorded. At 30 days and 60 days,the patency rate of every group was calculated. At 60 days IDs were measured, cell prol iferation in neointima was inspected by l ight microscope, morphology on neointima was observed by SEM. Results The ID of the PU vascular grafts was (3.74 ± 0.06) mm, wall thickness was 0.4-0.6 mm, the wall density was 0.25 g/cm3, the porosity was 79.8%, racical compl iance was 8.57%/100 mmHg. In the wall, micropores were well distributed and opened-pores structure was observed. Pore size was (140 ± 41) μm in the outside layer, pore size was (100 ± 3) μm in the inside layer, thickness ratio of outside / inside layers was 2 ∶ 1, the pore size was (40 ± 16) μm on the lumina surface. After operation the wounds on neck healed, all the animals survived and had no compl ication. At 30 days and 60 days after implantation, the patency rate for rF II -immobil ized PU group were 100% and 66.7%, for no rF II -immobil ized PU group were 66.7% and 33.3%, and for ePTFE group were 67.7% and 0 respectively, but at 60 days there were thrombosis at anastamotic sites of some grafts occluded. Before operation the IDs for rF II-immobil ized PU group, no rF II -immobil ized PU group and ePTFE group were (3.74 ± 0.06), (3.74 ± 0.06) and (4.00 ± 0.03) mm, at 60 days after operation the IDs were (4.51 ± 0.05), (4.31 ± 0.24) and (4.43 ± 0.12) mm respectively, showing no statistically significant differences between 3 groups (P gt; 0.05). Histological inspection indicated that at 15 days a layer of plasma protein deposited on the lumina, at 30 days some cells adhered to the lumina, at 60 days neointima could be observed on the lumina. Thickness of the neointima became larger with implantation time. At 60 days neointima thickness at proximal end, middle site and distal end ofgraft were (560 ± 22), (78 ± 5) and (323 ± 31) μm respectively for rF II -immobil ized PU group. The results of SEM showed that neointima surface consisted of flat and long cells which long axes ranged with blood flow direction and was similar to lumina morphology of carotid artery of dog. Conclusion Immobil ization of rF II to lumina of grafts could enhance fibrinolytic activity and inhibited formation of thrombo-embol ia which led to an increase in patency rate after implantation.
ObjectiveTo investigate the advantages of magnetic compressive anastomosis (MCA) for non-suture femoral artery anastomosis.
MethodsTwelve adult health mongrel dogs,weighing (16.5±3.6) kg,were selected for in situ end-to-end anastomosis of the femoral artery.One side of the femoral artery was anastomosised with MCA (group A) and the other side of the femoral artery was anastomosised by hand-suturing (group B).The anastomosis time,complications,and vascular bursting pressure were recorded.Gross observation,histological staining (HE and Masson),and scanning electron microscopy observation were performed at 2,4,12,and 24 weeks postoperatively.
ResultsThe anastomosis time in group A [(3.89±1.16) minutes] was significantly shorter than that in group B [(14.16±3.72) minutes] (t=14.226,P=0.000).The complication rate of group A (0) was significantly lower than that of group B (75%)(P=0.000).At immediate,4 and 12 weeks after operation,the vascular bursting pressure of anastomosis site in group A was more than 280 mm Hg (1 mm Hg=0.133 kPa),and was (140.11±15.23),(180.31±24.55),and more than 280 mm Hg in group B,showing significant differences at immediate and 4 weeks (P<0.05),but no significant difference at 12 weeks (P>0.05).In group A at 4 weeks,good intima contact,smooth endothelium,and regular arrangement of endothelial cells were observed;at 12 weeks,chronic inflammation was present,with a few lymphocytes infiltration;and at 24 weeks,inflammation significantly decreased.But in group B,obvious suture foreign body and scar formation were observed,which led to uneven surface with lumen incomplete intima,and irregular endothelial cells in arrangement disorder.
ConclusionCompared with traditional hand-suturing,the MCA has the advantages of shorter operation time,higher patency rate,less complication,and better healing at the anastomotic site.Non-suture anastomosis of the femoral artery by MCA can achieve reliable results.
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.
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 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.
Six dogs underwent high selective vagotomy and mucosal antrectomy (HSV+MA). The gross and histological change of dog’s stomach were observed at 4-6 months after operation. It was found that the reconstructed antrum healed well and there was no stasis and distension in the stomach .The appearance of the nerves in muscular layer of the antrum was normal. No serious gastritis and mucosal atrophy was observed. These results indicat that HSV+MA is a reasonable procedure for the treatment of duodenal ulcer.
